Molecules

2595 KiB

Open AccessReview

Structural and Biochemical Properties of Novel Self-Cleaving Ribozymes

by Ki-Young Lee and Bong-Jin Lee

Molecules 2017, 22(4), 678; https://doi.org/10.3390/molecules22040678 - 24 Apr 2017

Cited by 26 | Viewed by 9537

Fourteen well-defined ribozyme classes have been identified to date, among which nine are site-specific self-cleaving ribozymes. Very recently, small self-cleaving ribozymes have attracted renewed interest in their structure, biochemistry, and biological function since the discovery, during the last three years, of four novel [...] Read more.

Fourteen well-defined ribozyme classes have been identified to date, among which nine are site-specific self-cleaving ribozymes. Very recently, small self-cleaving ribozymes have attracted renewed interest in their structure, biochemistry, and biological function since the discovery, during the last three years, of four novel ribozymes, termed twister, twister sister, pistol, and hatchet. In this review, we mainly address the structure, biochemistry, and catalytic mechanism of the novel ribozymes. They are characterized by distinct active site architectures and divergent, but similar, biochemical properties. The cleavage activities of the ribozymes are highly dependent upon divalent cations, pH, and base-specific mutations, which can cause changes in the nucleotide arrangement and/or electrostatic potential around the cleavage site. It is most likely that a guanine and adenine in close proximity of the cleavage site are involved in general acid-base catalysis. In addition, metal ions appear to play a structural rather than catalytic role although some of their crystal structures have shown a direct metal ion coordination to a non-bridging phosphate oxygen at the cleavage site. Collectively, the structural and biochemical data of the four newest ribozymes could contribute to advance our mechanistic understanding of how self-cleaving ribozymes accomplish their efficient site-specific RNA cleavages. Full article

(This article belongs to the Special Issue Ribozymes and RNA Catalysis)

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Figure 1

Figure 1
Secondary and tertiary structures of two representatives of twister ribozymes. (A) The structure of the twister ribozyme from O. sativa [<a href="#B30-molecules-22-00678" class="html-bibr">30</a>]. Additional stem-loop segments, P3 and/or P5, can be generated, as shown in black dotted lines; (B) The structure of the env22 twister ribozyme [<a href="#B29-molecules-22-00678" class="html-bibr">29</a>]. In (A) and (B), red arrowhead indicates the U-A cleavage site. On the secondary structure, highly conserved nucleotides (>97%) are marked by asterisks. Stems (P1-P4) and pseudoknots (T1 and T2) are colour-coded in the tertiary structure. In particular, two nucleotides at the cleavage site and bound magnesium ions are coloured in cyan and yellow, respectively. Protein Data Bank (PDB) accession codes for (A) and (B) are 4OJI and 4RGE, respectively. Full article ">Figure 2
Sequence and secondary structure model of the TS-1 twister sister ribozyme [<a href="#B9-molecules-22-00678" class="html-bibr">9</a>] (A) and the Ht-1 hatchet ribozyme [<a href="#B11-molecules-22-00678" class="html-bibr">11</a>] (B). Highly conserved and non-native nucleotides are coloured in red and grey, respectively. The cleavage sites are indicated by red arrowheads. Full article ">Figure 3
Secondary and tertiary structures of the env25 pistol ribozyme [<a href="#B34-molecules-22-00678" class="html-bibr">34</a>]. On the secondary structure (left); highly conserved nucleotides are marked by asterisks, and red arrowhead indicates the G53-U54 cleavage site. Stems (P1-P3) and pseudoknots (T1) are colour-coded in the tertiary structure (right). In particular, two nucleotides at the cleavage site and bound magnesium ions are coloured in cyan and yellow, respectively. PDB accession code is 5K7C. Full article ">Figure 4
Internal phosphoester transfer mechanism for RNA cleavage. The 2′ oxygen nucleophile of a sugar attacks its adjacent phosphorus atom, together with subsequent protonation and departure of the 5′ oxygen of a sugar. Full article ">

2092 KiB

Open AccessArticle

UVA, UVB and UVC Light Enhances the Biosynthesis of Phenolic Antioxidants in Fresh-Cut Carrot through a Synergistic Effect with Wounding

by Bernadeth B. Surjadinata, Daniel A. Jacobo-Velázquez and Luis Cisneros-Zevallos

Molecules 2017, 22(4), 668; https://doi.org/10.3390/molecules22040668 - 24 Apr 2017

Cited by 95 | Viewed by 10601

Abstract

Previously, we found that phenolic content and antioxidant capacity (AOX) in carrots increased with wounding intensity. It was also reported that UV radiation may trigger the phenylpropanoid metabolism in plant tissues. Here, we determined the combined effect of wounding intensity and UV radiation [...] Read more.

Previously, we found that phenolic content and antioxidant capacity (AOX) in carrots increased with wounding intensity. It was also reported that UV radiation may trigger the phenylpropanoid metabolism in plant tissues. Here, we determined the combined effect of wounding intensity and UV radiation on phenolic compounds, AOX, and the phenylalanine ammonia-lyase (PAL) activity of carrots. Accordingly, phenolic content, AOX, and PAL activity increased in cut carrots with the duration of UVC radiation, whereas whole carrots showed no increase. Carrot pies showed a higher increase compared to slices and shreds. Phenolics, AOX, and PAL activity also increased in cut carrots exposed to UVA or UVB. The major phenolics were chlorogenic acid and its isomers, ferulic acid, and isocoumarin. The type of UV radiation affected phenolic profiles. Chlorogenic acid was induced by all UV radiations but mostly by UVB and UVC, ferulic acid was induced by all UV lights to comparable levels, while isocoumarin and 4,5-diCQA was induced mainly by UVB and UVC compared to UVA. In general, total phenolics correlated linearly with AOX for all treatments. A reactive oxygen species (ROS) mediated hypothetical mechanism explaining the synergistic effect of wounding and different UV radiation stresses on phenolics accumulation in plants is herein proposed. Full article

(This article belongs to the Special Issue Recent Advances in Plant Phenolics)

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Figure 1
Total phenolic content (A); antioxidant capacity (B); and phenylalanine ammonia-lyase (PAL) activity (C) of carrots cuts (A/W) including whole, slices, pies and shreds radiated with different doses of UVC (11.8 Watts/m2 for 0, 0.5, 1 and 15 min). Measurements were taken after 4 d of storage at 15 °C. All quantifications were on fresh weight basis. Vertical bars represent standard deviations (n = 5). Full article ">Figure 2
Total phenolic content (A); antioxidant capacity (B); and PAL activity (C) of carrot pies radiated with different UV lights (light intensities of 11.8, 10.4 and 12.7 W/m2 for UVC, UVB and UVA, respectively). Measurements were taken after 4 d of storage at 15 °C. All quantifications were on fresh weight basis. Vertical bars represent standard deviations (n = 5). Full article ">Figure 3
Effect of different UV radiations on individual phenolic compounds of carrot tissue; chlorogenic acid (5-CQA) (A); ferulic acid (FA) (B); 4,5-dicaffeoylquinic acid (4,5-diCQA) (C); and isocoumarin (D). Measurements were taken after 4 d of storage at 15 °C. All quantifications were on fresh weight basis. Vertical bars represent standard deviations (n = 5). Bars with different letters indicate statistical difference (p < 0.05). Full article ">Figure 4
Proposed model explaining the synergistic effect of wounding and UVA, UVB and UVC radiation stresses on phenolics accumulation in carrots. UV radiation produces reactive oxygen species (ROS) as a primary signal for the activation of PAL and for the accumulation of phenolics. ROS production induced by UV is triggered by increasing mitochondrial respiration and by water ionization. The skin/cuticle of plants contains UV light-filtering compounds, thus the amount of ROS induced by UV would be tissue-dependent. When wounding is applied prior to UV radiation, the skin/cuticle would be partially removed, and thus the area for the penetration of radiation is increased, leading to higher ROS production, increased PAL activity and phenolics accumulation. On the other hand, wounding has its own mechanism of ROS production. For wounding, ATP acts as the primary signal for the production of ROS which acts like a secondary signal increasing the levels of PAL and phenolics. Abbreviations: SOD (superoxide dismutase); PAL (phenylalanine ammonia-lyase); ROS (reactive oxygen species); k1 (rate of phenolic biosynthesis); k2 (rate of phenolic utilization). Full article ">

6326 KiB

Open AccessArticle

Inhibitory Effect of Triterpenoids from Panax ginseng on Coagulation Factor X

by Lingxin Xiong, Zeng Qi, Bingzhen Zheng, Zhuo Li, Fang Wang, Jinping Liu and Pingya Li

Molecules 2017, 22(4), 649; https://doi.org/10.3390/molecules22040649 - 24 Apr 2017

Cited by 24 | Viewed by 6061

Abstract

Enzymes involved in the coagulation process have received great attention as potential targets for the development of oral anti-coagulants. Among these enzymes, coagulation factor Xa (FXa) has remained the center of attention in the last decade. In this study, 16 ginsenosides and two [...] Read more.

Enzymes involved in the coagulation process have received great attention as potential targets for the development of oral anti-coagulants. Among these enzymes, coagulation factor Xa (FXa) has remained the center of attention in the last decade. In this study, 16 ginsenosides and two sapogenins were isolated, identified and quantified. To determine the inhibitory potential on FXa, the chromogenic substrates method was used. The assay suggested that compounds 5, 13 and 18 were mainly responsible for the anti-coagulant effect. Furthermore, these three compounds also possessed high thrombin selectivity in the thrombin inhibition assay. Furthermore, Glide XP from Schrödinger was employed for molecular docking to clarify the interaction between the bioactive compounds and FXa. Therefore, the chemical and biological results indicate that compounds 5 (ginsenoside Rg2), 13 (ginsenoside Rg3) and 18 (protopanaxtriol, PPT) are potential natural inhibitors against FXa. Full article

(This article belongs to the Special Issue Current Trends in Ginseng Research)

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4173 KiB

Open AccessFeature PaperArticle

Photocatalytic and Adsorption Performances of Faceted Cuprous Oxide (Cu₂O) Particles for the Removal of Methyl Orange (MO) from Aqueous Media

by Weng Chye Jeffrey Ho, Qiuling Tay, Huan Qi, Zhaohong Huang, Jiao Li and Zhong Chen

Molecules 2017, 22(4), 677; https://doi.org/10.3390/molecules22040677 - 23 Apr 2017

Cited by 90 | Viewed by 9376

Abstract

Particles of sub-micron size possess significant capacity to adsorb organic molecules from aqueous media. Semiconductor photocatalysts in particle form could potentially be utilized for dye removal through either physical adsorption or photo-induced chemical process. The photocatalytic and adsorption capabilities of Cu₂O [...] Read more.

Particles of sub-micron size possess significant capacity to adsorb organic molecules from aqueous media. Semiconductor photocatalysts in particle form could potentially be utilized for dye removal through either physical adsorption or photo-induced chemical process. The photocatalytic and adsorption capabilities of Cu₂O particles with various exposed crystal facets have been studied through separate adsorption capacity test and photocatalytic degradation test. These crystals display unique cubic, octahedral, rhombic dodecahedral, and truncated polyhedral shapes due to specifically exposed crystal facet(s). For comparison, Cu₂O particles with no clear exposed facets were also prepared. The current work confirms that the surface charge critically affects the adsorption performance of the synthesized Cu₂O particles. The octahedral shaped Cu₂O particles, with exposed {111} facets, possess the best adsorption capability of methyl orange (MO) dye due to the strongest positive surface charge among the different types of particles. In addition, we also found that the adsorption of MO follows the Langmuir monolayer mechanism. The octahedral particles also performed the best in photocatalytic dye degradation of MO under visible light irradiation because of the assistance from dye absorption. On top of the photocatalytic study, the stability of these Cu₂O particles during the photocatalytic processes was also investigated. Cu(OH)₂ and CuO are the likely corrosion products found on the particle surface after the photocorrosion in MO solution. By adding hole scavengers in the solution, the photocorrosion of Cu₂O was greatly reduced. This observation confirms that the photocatalytically generated holes were responsible for the photocorrosion of Cu₂O. Full article

(This article belongs to the Special Issue Photon-involving Purification of Water and Air)

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5360 KiB

Open AccessReview

Adenosine A1 and A2A Receptors in the Brain: Current Research and Their Role in Neurodegeneration

by Jocelyn Stockwell, Elisabet Jakova and Francisco S. Cayabyab

Molecules 2017, 22(4), 676; https://doi.org/10.3390/molecules22040676 - 23 Apr 2017

Cited by 139 | Viewed by 16045

Abstract

The inhibitory adenosine A1 receptor (A1R) and excitatory A2A receptor (A2AR) are predominantly expressed in the brain. Whereas the A2AR has been implicated in normal aging and enhancing neurotoxicity in multiple neurodegenerative diseases, the inhibitory A1R has traditionally been ascribed to have a [...] Read more.

The inhibitory adenosine A1 receptor (A1R) and excitatory A2A receptor (A2AR) are predominantly expressed in the brain. Whereas the A2AR has been implicated in normal aging and enhancing neurotoxicity in multiple neurodegenerative diseases, the inhibitory A1R has traditionally been ascribed to have a neuroprotective function in various brain insults. This review provides a summary of the emerging role of prolonged A1R signaling and its potential cross-talk with A2AR in the cellular basis for increased neurotoxicity in neurodegenerative disorders. This A1R signaling enhances A2AR-mediated neurodegeneration, and provides a platform for future development of neuroprotective agents in stroke, Parkinson’s disease and epilepsy. Full article

(This article belongs to the Special Issue Adenosine Receptors)

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Figure 1
Adenosine A1R activation induces neuronal death in vivo. (A) Representative confocal microscopy images showing hippocampal slices stained with propidium iodide, a fluorescent marker for cell death. Male Sprague-Dawley rats were given intraperitoneal (i.p.) injections of CPA (5 mg/kg) or CPA (5 mg/kg) + DPCPX (3 mg/kg) and sacrificed at 48 h following initial injection. Acute coronal brain slices were taken and stained with propidium iodide. In animals treated with CPA alone, there was significantly increased propidium iodide fluorescence, indicating increased cell death in the hippocampus. DPCPX treatment prevented CPA-induced neuronal death. Scale bar 0.5 mm; (B) Confocal microscopy images of area CA1 of rat hippocampal slices with the same in vivo treatments above. DAPI, a nuclear stain is shown in blue (far left panels), single-stranded DNA (ssDNA) shown in green (second from left panels), NeuN shown in red (second from right panels), and a merge of all three channels shown in the far right panels. The marker ssDNA was used to label apoptotic cells, while NeuN (a neuronal marker) was used to label the CA1 cell layer. CPA treatment caused increased ssDNA staining in CA1 compared to control and DPCPX + CPA treated brains, indicating that CPA treatment was pro-apoptotic. Scale bar 30 µm. Full article ">Figure 2
Proposed signaling cascade induced by A1R and A2AR activation. This figure represents our proposed interaction between A1Rs and A2ARs and how they interact to modulate the surface expression of AMPA receptors and also our proposed mechanism of cross-talk through CK2 activation. Abbreviations: A1R—adenosine A1 receptor, GluA1 and GluA2—subunits of AMPA receptors, A2AR—adenosine A2A receptor, JNK—C-jun N-terminal kinase, p38—p38 mitogen-activated protein kinase (MAPK), PP2A—protein phosphatase 2A, PP1—protein phosphatase 1, PP2B—protein phosphatase 2B, PKA—protein kinase A, cAMP—cyclic adenosine monophosphate, AC—adenylyl cyclase, CK2—protein kinase CK2. Full article ">

2839 KiB

Open AccessArticle

High-Performance Prediction of Human Estrogen Receptor Agonists Based on Chemical Structures

by Yuki Asako and Yoshihiro Uesawa

Molecules 2017, 22(4), 675; https://doi.org/10.3390/molecules22040675 - 23 Apr 2017

Cited by 7 | Viewed by 5237

Abstract

Many agonists for the estrogen receptor are known to disrupt endocrine functioning. We have developed a computational model that predicts agonists for the estrogen receptor ligand-binding domain in an assay system. Our model was entered into the Tox21 Data Challenge 2014, a computational [...] Read more.

Many agonists for the estrogen receptor are known to disrupt endocrine functioning. We have developed a computational model that predicts agonists for the estrogen receptor ligand-binding domain in an assay system. Our model was entered into the Tox21 Data Challenge 2014, a computational toxicology competition organized by the National Center for Advancing Translational Sciences. This competition aims to find high-performance predictive models for various adverse-outcome pathways, including the estrogen receptor. Our predictive model, which is based on the random forest method, delivered the best performance in its competition category. In the current study, the predictive performance of the random forest models was improved by strictly adjusting the hyperparameters to avoid overfitting. The random forest models were optimized from 4000 descriptors simultaneously applied to 10,000 activity assay results for the estrogen receptor ligand-binding domain, which have been measured and compiled by Tox21. Owing to the correlation between our model’s and the challenge’s results, we consider that our model currently possesses the highest predictive power on agonist activity of the estrogen receptor ligand-binding domain. Furthermore, analysis of the optimized model revealed some important features of the agonists, such as the number of hydroxyl groups in the molecules. Full article

(This article belongs to the Special Issue Computational Analysis for Protein Structure and Interaction)

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Figure 1
Scheme of the model construction. Full article ">Figure 2
Charged and uncharged forms 100 random forest (RF) models were constructed for the charged, uncharged, and both forms of each descriptor. All models were involved in predicting the activities of the estrogen receptor ligand-binding domain for the compounds in the final evaluation set. 100 ROC_AUC values were plotted for each group. Green lines denote the averages and their 95% confidence intervals. Full article ">Figure 3
Number of descriptors 100 RF models were constructed for both numbers of descriptors. All models were involved in predicting the activities of estrogen receptor ligand-binding domain for compounds in the final evaluation set. 100 ROC_AUC values were plotted for each group. Green lines denote the averages and their 95% confidence intervals. Full article ">Figure 4
Relationship between ROC_AUC values in models constructed from the test set (50%) and the final evaluation set. Each point denotes the performance of the model. This figure is referred from [<a href="#B9-molecules-22-00675" class="html-bibr">9</a>]. Full article ">Figure 5
Effects of the hyperparameter Number of Terms on the RF modeling 190 RF models were constructed in each group, and all models were then involved in predicting the activities of the estrogen receptor ligand-binding domain for compounds in the final evaluation set. Plotted are the ROC_AUC values for the final evaluation set in each group. Green lines denote the averages and their 95% confidence intervals. Full article ">Figure 6
Effects of the hyperparameter Maximum Splits per Tree on the RF modeling ROC_AUC values of the training set (50%) and final evaluation set are plotted in closed and open circles, respectively. Large Maximum Splits per Tree introduced model overfitting. The predictive ability was optimized for Maximum Splits per Tree = 6. Full article ">Figure 7
ROC curves for predicting ER-LBD-activating compounds with the newly proposed model (left) and the best model of the Tox21 Data Challenge 2014 ROC-AUCs and hyperparameter values in the models are also described. Full article ">

2684 KiB

Open AccessArticle

Production of Laccase by a New Myrothecium verrucaria MD-R-16 Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.] and its Application on Dye Decolorization

by Jiao Sun, Na Guo, Li-Li Niu, Qing-Fang Wang, Yu-Ping Zang, Yuan-Gang Zu and Yu-Jie Fu

Molecules 2017, 22(4), 673; https://doi.org/10.3390/molecules22040673 - 23 Apr 2017

Cited by 36 | Viewed by 6072

Abstract

The present study was conducted to screen a laccase-producing fungal endophyte, optimize fermentation conditions, and evaluate the decolorization ability of the laccase. A new fungal endophyte capable of laccase-producing was firstly isolated from pigeon pea and identified as Myrothecium verrucaria based on a [...] Read more.

The present study was conducted to screen a laccase-producing fungal endophyte, optimize fermentation conditions, and evaluate the decolorization ability of the laccase. A new fungal endophyte capable of laccase-producing was firstly isolated from pigeon pea and identified as Myrothecium verrucaria based on a ITS-rRNA sequences analysis. Meanwhile, various fermentation parameters on the laccase production were optimized via response surface methodology (RSM). The optimal fermentation conditions were a fermentation time of five days, temperature 30 °C and pH 6.22. Laccase activity reached 16.52 ± 0.18 U/mL under the above conditions. Furthermore, the laccase showed effective decolorization capability toward synthetic dyes (Congo red, Methyl orange, Methyl red, and Crystal violet) in the presence of the redox mediator ABTS, with more than 70% of dyes decolorizing after 24 h of incubation. Additionally, the activity of laccase was relatively stable with pH (4.5–6.5) and a temperature range of 35–55 °C. Therefore, the high laccase production of the strain and the new fungal laccase could provide a promising alterative approach for industrial and environmental applications. Full article

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Figure 1
Laccase-producing fungal endophyte isolated from pigeon pea. (A) laccase-producing fungal endophyte on the potato dextrose agar (PDA) without guaiacol; (B) laccase-producing fungal endophyte on the PDA with laccase indicator-guaiacol; (C) and (D) represented the fungal endophyte MD-R-16 of colonial morphology and micrographic characteristics (×400), respectively; (E) phylogenetic tree constructed by the program neighbor-joining (NJ) based on ITS1-5.8S-ITS2 sequences of laccase-producing fungal endophyte. Bootstrap values (1000 tree interactions) are indicated at the nodes. Full article ">Figure 2
Effects of nutrient and fermentation factors on laccase production by M. verrucaria MD-R-16. (A) Effect of carbon sources on laccase production. The carbon source (from a–e) is successively glucose, sucrose, starch, lactose, and maltose. (B) Effect of nitrogen sources on laccase production. The nitrogen source (from a–e) is successively yeast extract, peptone, beef extract, ammonium chloride, and ammonium nitrate. (C) Effect of fermentation time on laccase production. (D) Effect of temperature on laccase production. (E) Effect of initial pH values on laccase production. All experiments are done by changing one independent variable while fixing others at certain levels. Full article ">Figure 3
Response surfaces plots for the laccase production by M. verrucaria MD-R-16: (A) varying the fermentation temperature and time; (B) varying the fermentation time and pH of the initial fermentation medium; (C) varying the fermentation temperature and pH of the initial fermentation medium. Full article ">Figure 4
Effects of reaction time on the decolorization of different dyes (CR, MO, MR, CV) in laccase or an ABTS-laccase mediated system. Data were expressed as mean ± SD (n = 3). Full article ">Figure 5
Effects of different parameters on MR decolorization in an ABTS-laccase mediated system: (A) pH; (B) Temperature; (C) ABTS concentration. Data were expressed as mean ± SD (n = 3). Full article ">

1773 KiB

Open AccessCommunication

Modified Nucleotides as Substrates of Terminal Deoxynucleotidyl Transferase

by Daiva Tauraitė, Jevgenija Jakubovska, Julija Dabužinskaitė, Maksim Bratchikov and Rolandas Meškys

Molecules 2017, 22(4), 672; https://doi.org/10.3390/molecules22040672 - 22 Apr 2017

Cited by 18 | Viewed by 9642

Abstract

The synthesis of novel modified nucleotides and their incorporation into DNA sequences opens many possibilities to change the chemical properties of oligonucleotides (ONs), and, therefore, broaden the field of practical applications of modified DNA. The chemical synthesis of nucleotide derivatives, including ones bearing [...] Read more.

The synthesis of novel modified nucleotides and their incorporation into DNA sequences opens many possibilities to change the chemical properties of oligonucleotides (ONs), and, therefore, broaden the field of practical applications of modified DNA. The chemical synthesis of nucleotide derivatives, including ones bearing thio-, hydrazino-, cyano- and carboxy groups as well as 2-pyridone nucleobase-containing nucleotides was carried out. The prepared compounds were tested as substrates of terminal deoxynucleotidyl transferase (TdT). The nucleotides containing N⁴-aminocytosine, 4-thiouracil as well as 2-pyridone, 4-chloro- and 4-bromo-2-pyridone as a nucleobase were accepted by TdT, thus allowing enzymatic synthesis of 3’-terminally modified ONs. The successful UV-induced cross-linking of 4-thiouracil-containing ONs to TdT was carried out. Enzymatic post-synthetic 3’-modification of ONs with various photo- and chemically-reactive groups opens novel possibilities for future applications, especially in analysis of the mechanisms of polymerases and the development of photo-labels, sensors, and self-assembling structures. Full article

(This article belongs to the Special Issue Nucleoside and Nucleotide Analogues)

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Figure 1
Polyacrylamide gel electrophoresis (PAGE) analysis of primer extension reactions (PEX) with terminal deoxynucleotidyl transferase (TdT) in glutamate/Mg2+ buffer. Lane 1, primer labelled at the 5'-end with a radioactive isotope of phosphorus (5’-33P-labelled primer); lanes 2–12, products of PEX using: lane 2, 2’-deoxythymidine triphosphate (dTTP); lane 3, 2’-deoxyuridine triphosphate (dUTP); lane 4, 2’-deoxycytidine triphosphate (dCTP); lane 5, 2-pyridone-2’-deoxyriboside triphosphate (dPyrTP); lane 6, dPyr4OHTP; lane 7, dPyr4ClTP; lane 8, dPyr4BrTP; lane 9, dPyr5COOHTP; lane 10, 4-thio-dUTP; lane 11, dU5CNTP; lane 12, dU5COOHTP; lane 13, N4-amino-dCTP. Full article ">Figure 2
PAGE analysis of PEX with TdT in cacodylate/Co2+ buffer. Lane 1, 5′-33P-labelled primer; lanes 2–12, products of PEX using: lane 2, dTTP; lane 3, dUTP; lane 4, dCTP; lane 5, dPyrTP; lane 6, dPyr4OHTP; lane 7, dPyr4ClTP; lane 8, dPyr4BrTP; lane 9, dPyr5COOHTP; lane 10, 4-thio-dUTP; lane 11, dU5CNTP; lane 12, dU5COOHTP; lane 13, N4-amino-dCTP. Full article ">Figure 3
PAGE analysis of cross-linked complexes of 4-thio-dU-ONs and TdT. Lane 1, recombinant TdT; lane 2, molecular mass marker (kDa); lane 3, 4-thio-dU-ON:TdT UV-free control; lane 4, cross-linked complexes of 4-thio-dU-ON:TdT, dose of UV irradiation ~17.2 J/cm2; lane 5, cross-linked complexes of 4-thio-dU-ON:TdT, dose of UV irradiation ~4.6 J/cm2; lane 6, cross-linked complexes of 4-thio-dU-ON:TdT (excess of TdT), dose of UV irradiation ~17.2 J/cm2; lane 7; dU-ON:TdT control, dose of UV irradiation ~17.2 J/cm2. Full article ">Scheme 1
Synthesis of 4-thio-2’-deoxyuridine triphosphate (3) and N4-amino-2’-deoxycytidine triphosphate (4). Reagents and conditions: (i) Ac2O, NaOAc, 90 °C, 30 min; (ii) Lawesson’s reagent, toluene, 90 °C, 2 h; (iii) NaOCH3, CH3OH, rt, 30 min; (iv) POCl3, Bu3N, trimethyl phosphate, 0 °C, 90 min; then Bu3N, (NHBu3)2H2P2O7, CH3CN, 0 °C, 15 min; (v) NH2-NH2, H2O, rt, 18 h. Full article ">Scheme 2
Synthesis of 5-cyano- and 5-carboxy-dUTP. Reagents and conditions: (i) 1,1,1,3,3,3-hexamethyldisilazane (HMDS), trimethylsilyl chloride (TMSCl), 80 °C, 4h; then 1,3,5-O-triacetyl-2-deoxyribose, SnCl4, rt, 5 h; (ii) NaOCH3, CH3OH, rt, 30 min; (iii) POCl3, Bu3N, trimethyl phosphate, 0–4 °C, 2–3 h; then Bu3N, (NHBu3)2H2P2O7, CH3CN, 0 °C, 10–15 min. Full article ">

2486 KiB

Open AccessArticle

Effects of Flavonoids and Triterpene Analogues from Leaves of Eleutherococcus sieboldianus (Makino) Koidz. ‘Himeukogi’ in 3T3-L1 Preadipocytes

by Atsuyoshi Nishina, Masaya Itagaki, Yuusuke Suzuki, Mamoru Koketsu, Masayuki Ninomiya, Daisuke Sato, Takashi Suzuki, Satoshi Hayakawa, Makoto Kuroda and Hirokazu Kimura

Molecules 2017, 22(4), 671; https://doi.org/10.3390/molecules22040671 - 22 Apr 2017

Cited by 16 | Viewed by 5318

Abstract

Eleutherococcus sieboldianus (Makino) Koidz. is a local product from the area in and around Yonezawa City in Yamagata Prefecture, Japan. It has been used as a medicinal plant for a long time. We isolated and identified four types of flavonoid glycosides [astragalin ( [...] Read more.

Eleutherococcus sieboldianus (Makino) Koidz. is a local product from the area in and around Yonezawa City in Yamagata Prefecture, Japan. It has been used as a medicinal plant for a long time. We isolated and identified four types of flavonoid glycosides [astragalin (1), isoquercetin (2), rhamnocitrin 3-O-glucoside (3), and nicotiflorin (4)], a triterpene [methyl hederagenin (5)], and three types of triterpene glycosides [δ-hederin (6), echinocystic acid 3-O-arabinoside (7), and cauloside B (8)] from the methanol extract of E. sieboldianus, which regulates lipid accumulation in 3T3-L1 preadipocytes. Among the compounds isolated, 2 and 8 up- and down-regulated lipid accumulation and insulin induced adipocyte differentiation in 3T3-L1 preadipocytes. Compound 2 induced up-regulation of lipid accumulation and decreased adipocyte size, while 8 down-regulated lipid accumulations without decreasing cell size. Additionally, 2 increased adipogenic proteins [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and fatty-acid-binding protein 4 (FABP4)]. In contrast, 8 decreased the levels of all adipogenic proteins and glucose transporter type 4 (GLUT4), but increased adiponectin. Full article

(This article belongs to the Special Issue Plant Polyphenols as Potential Therapeutic Agents for Diabetes and Obesity)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Cytotoxic effects of the three extracts and eight compounds isolated from E. sieboldianus in 3T3L1 cells. Data are expressed as the mean ± SD from three independent experiments. The same letters indicate that there are no differences between those groups, and different letters indicate significant differences (p < 0.05). Full article ">Figure 2
The effects of the three extracts and eight compounds isolated from E. sieboldianus on triglycerol levels in 3T3-L1 cells. The 3T3-L1 cells were cultured in 24-well plates and differentiated under the conditions described in the materials and methods section for each compound. Undifferentiated cells, cells with the addition of the MDI mixture (a mixture of 0.5 mM 3-isobutyl-1-methyl xanthine (M), 0.1 μM dexamethasone (D), and 2 μM insulin (I)), rosiglitazone, and berberine, are indicated by CTRL, INS, ROS, and BER, respectively. On day 8 of culturing, the medium was removed and cells were lysed using Ripa buffer. Triglycerol levels were determined by the Triglycerol E-test Wako (Wako Pure Chemical, Osaka, Japan). Data are presented as the mean ± SD from three independent experiments. The same letters indicate that there are no differences between those groups, and different letters indicate significant differences (p < 0.05). Full article ">Figure 3
Compounds isolated from E. sieboldianus. Full article ">Figure 4
Merged phase differences and fluorescent images of differentiated 3T3-L1 cells on day 8 with reference compounds, 2, and 8. The 3T3-L1 cells were cultured in 24-well plates and differentiated with each compound under the conditions described in the materials and methods section. Fluorescent staining of intracellular lipids was accomplished by adding BODIPY® 493/503 to the medium. Undifferentiated cells, cells with the addition of MDI mixture, rosiglitazone, and berberine are indicated by CTRL, INS, ROS, and BER respectively. Full article ">Figure 5
The effects of each compound on adipogenesis-related protein levels in 3T3-L1 cells during adipogenesis. The cells were differentiated under the conditions shown in <a href="#molecules-22-00671-f004" class="html-fig">Figure 4</a>. Protein levels were measured by electroblotting. Data are presented as the mean ± SD from three independent experiments. The same letters indicate no differences between groups, and different letters indicate significant differences (p < 0.05). Full article ">

3774 KiB

Open AccessArticle

Multiple UDP-Glucuronosyltransferase and Sulfotransferase Enzymes are Responsible for the Metabolism of Verproside in Human Liver Preparations

by Ju-Hyun Kim, Deok-Kyu Hwang, Ju-Yeon Moon, Yongnam Lee, Ji Seok Yoo, Dae Hee Shin and Hye Suk Lee

Molecules 2017, 22(4), 670; https://doi.org/10.3390/molecules22040670 - 22 Apr 2017

Cited by 6 | Viewed by 4487

Abstract

Verproside, an active iridoid glycoside component of Veronica species, such as Pseudolysimachion rotundum var. subintegrum and Veronica anagallis-aquatica, possesses anti-asthma, anti-inflammatory, anti-nociceptive, antioxidant, and cytostatic activities. Verproside is metabolized into nine metabolites in human hepatocytes: verproside glucuronides (M1, M2) [...] Read more.

Verproside, an active iridoid glycoside component of Veronica species, such as Pseudolysimachion rotundum var. subintegrum and Veronica anagallis-aquatica, possesses anti-asthma, anti-inflammatory, anti-nociceptive, antioxidant, and cytostatic activities. Verproside is metabolized into nine metabolites in human hepatocytes: verproside glucuronides (M1, M2) via glucuronidation, verproside sulfate (M3) via sulfation, picroside II (M4) and isovanilloylcatalpol (M5) via O-methylation, M4 glucuronide (M6) and M4 sulfate (M8) via further glucuronidation and sulfation of M4, and M5 glucuronide (M7) and M5 sulfate (M9) via further glucuronidation and sulfation of M5. Drug-metabolizing enzymes responsible for verproside metabolism, including sulfotransferase (SULT) and UDP-glucuronosyltransferase (UGT), were characterized. The formation of verproside glucuronides (M1, M2), isovanilloylcatalpol glucuronide (M7), and picroside II glucuronide (M6) was catalyzed by commonly expressed UGT1A1 and UGT1A9 and gastrointestinal-specific UGT1A7, UGT1A8, and UGT1A10, consistent with the higher intrinsic clearance values for the formation of M1, M2, M6, and M7 in human intestinal microsomes compared with those in liver microsomes. The formation of verproside sulfate (M3) and M5 sulfate (M9) from verproside and isovanilloylcatalpol (M5), respectively, was catalyzed by SULT1A1. Metabolism of picroside II (M4) into M4 sulfate (M8) was catalyzed by SULT1A1, SULT1E1, SULT1A2, SULT1A3, and SULT1C4. Based on these results, the pharmacokinetics of verproside may be affected by the co-administration of relevant UGT and SULT inhibitors or inducers. Full article

(This article belongs to the Section Medicinal Chemistry)

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1419 KiB

Open AccessReview

Polyphenolic Compounds and Digestive Enzymes: In Vitro Non-Covalent Interactions

by Alejandra I. Martinez-Gonzalez, Ángel G. Díaz-Sánchez, Laura A. de la Rosa, Claudia L. Vargas-Requena, Ismael Bustos-Jaimes and And Emilio Alvarez-Parrilla

Molecules 2017, 22(4), 669; https://doi.org/10.3390/molecules22040669 - 22 Apr 2017

Cited by 167 | Viewed by 12910

Abstract

The digestive enzymes–polyphenolic compounds (PCs) interactions behind the inhibition of these enzymes have not been completely studied. The existing studies have mainly analyzed polyphenolic extracts and reported inhibition percentages of catalytic activities determined by UV-Vis spectroscopy techniques. Recently, pure PCs and new methods [...] Read more.

The digestive enzymes–polyphenolic compounds (PCs) interactions behind the inhibition of these enzymes have not been completely studied. The existing studies have mainly analyzed polyphenolic extracts and reported inhibition percentages of catalytic activities determined by UV-Vis spectroscopy techniques. Recently, pure PCs and new methods such as isothermal titration calorimetry and circular dichroism have been applied to describe these interactions. The present review focuses on PCs structural characteristics behind the inhibition of digestive enzymes, and progress of the used methods. Some characteristics such as molecular weight, number and position of substitution, and glycosylation of flavonoids seem to be related to the inhibitory effect of PCs; also, this effect seems to be different for carbohydrate-hydrolyzing enzymes and proteases. The digestive enzyme–PCs molecular interactions have shown that non-covalent binding, mostly by van der Waals forces, hydrogen binding, hydrophobic binding, and other electrostatic forces regulate them. These interactions were mainly associated to non-competitive type inhibitions of the enzymatic activities. The present review emphasizes on the digestive enzymes such as α-glycosidase (AG), α-amylase (PA), lipase (PL), pepsin (PE), trypsin (TP), and chymotrypsin (CT). Existing studies conducted in vitro allow one to elucidate the characteristics of the structure–function relationships, where differences between the structures of PCs might be the reason for different in vivo effects. Full article

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Graphical abstract

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Full article ">Figure 1
The chemical structures of some representative polyphenolic compounds examples, (a) gallic acid; (b) p-coumaric acid; (c) luteolin (d) quercetin; (e) (−)-epicatechin; (f) cyanidin-3-o-glucoside; (g) ellagic acid; and (h) proanthocyanidin A1. Full article ">Figure 2
Example of digestive enzymatic activity. An abstract of main carbohydrate-hydrolyzing enzymes, α-glucosidase and α-amylases isoforms, over starch is presented. Full article ">Figure 3
Three-dimensional structures of digestive enzymes: (a) α-glucosidase (PDB accession No.: 2QLY); (b) pancreatic α-amylase (No.: 1PIF2); (c) pancreatic lipase (No.: 1ETH); (d) pepsin (No.: 1YX9) and (e) trypsin (No.: 1S81). Domains A, B and C are presented in yellow, red and green colors, respectively; while domains D and E of α-glucosidase are presented in orange and gray colors, respectively. Colipase in pancreatic lipase is presented in blue color. The amino acid residues from the active site of each enzyme are colored: pink for Asp, blue for Glu, aquamarine for Ser, and purple for His. Ca2+ ion is a green-colored dot. Full article ">Figure 4
Non-covalent binding involves in the PCs–enzymes interactions. Examples of (a) van der Waals forces; (b) hydrogen binding; (c) hydrophobic binding; and (d) electrostatic forces. The protein chain is represented by R and curved line. Full article ">

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Open AccessArticle

Phenolic Compounds Isolated from Caesalpinia coriaria Induce S and G2/M Phase Cell Cycle Arrest Differentially and Trigger Cell Death by Interfering with Microtubule Dynamics in Cancer Cell Lines

by Jessica Nayelli Sánchez-Carranza, Laura Alvarez, Silvia Marquina-Bahena, Enrique Salas-Vidal, Verónica Cuevas, Elizabeth W. Jiménez, Rafael A. Veloz G., Maelle Carraz and Leticia González-Maya

Molecules 2017, 22(4), 666; https://doi.org/10.3390/molecules22040666 - 22 Apr 2017

Cited by 36 | Viewed by 7283

Abstract

Caesalpinia coriaria (C. coriaria), also named cascalote, has been known traditionally in México for having cicatrizing and inflammatory properties. Phytochemical reports on Caesalpinia species have identified a high content of phenolic compounds and shown antineoplastic effects against cancer cells. The aim [...] Read more.

Caesalpinia coriaria (C. coriaria), also named cascalote, has been known traditionally in México for having cicatrizing and inflammatory properties. Phytochemical reports on Caesalpinia species have identified a high content of phenolic compounds and shown antineoplastic effects against cancer cells. The aim of this study was to isolate and identify the active compounds of a water:acetone:ethanol (WAE) extract of C. coriaria pods and characterize their cytotoxic effect and cell death induction in different cancer cell lines. The compounds isolated and identified by chromatography and spectroscopic analysis were stigmasterol, ethyl gallate and gallic acid. Cytotoxic assays on cancer cells showed different ranges of activities. A differential effect on cell cycle progression was observed by flow cytometry. In particular, ethyl gallate and tannic acid induced G2/M phase cell cycle arrest and showed interesting effect on microtubule stabilization in Hep3B cells observed by immunofluorescence. The induction of apoptosis was characterized by morphological characteristic changes, and was supported by increases in the ratio of Bax/Bcl-2 expression and activation of caspase 3/7. This work constitutes the first phytochemical and cytotoxic study of C. coriaria and showed the action of its phenolic constituents on cell cycle, cell death and microtubules organization. Full article

(This article belongs to the Section Natural Products Chemistry)

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Figure 1
Compounds isolated from the WAE extract of C. coriaria. Full article ">Figure 2
Effect of the WAE extract of C. coriaria, GA, EG and TA on cell cycle progression in cancer cells lines. (A) PC3 (prostate); (B) Hep3B and (C) HepG2 (hepatocellular carcinoma); (D) HeLa and 2E) Caski (cervical cancer). Podophillotoxin (PDX) was used as a positive control (0.005 µM). * p < 0.05, ** p < 0.01, *** p < 0.001 compared with the control group. Full article ">Figure 2 Cont.
Effect of the WAE extract of C. coriaria, GA, EG and TA on cell cycle progression in cancer cells lines. (A) PC3 (prostate); (B) Hep3B and (C) HepG2 (hepatocellular carcinoma); (D) HeLa and 2E) Caski (cervical cancer). Podophillotoxin (PDX) was used as a positive control (0.005 µM). * p < 0.05, ** p < 0.01, *** p < 0.001 compared with the control group. Full article ">Figure 3
Effect of isolated compounds on stabilization of microtubules in Hep3B cells by immunofluorescence of α-Tubulin and confocal microscopy. EG; GA; TA; Podophillotoxin (Microtubules destabilizing agent) and Taxol (Microtubules stabilizing agent). Full article ">Figure 4
Effect of WAE extract of C. coriaria extract and pure compounds on cell death in Hep3B cells by epifluorescence microscopy. (A) Negative control; (B) C. coriaria extract; (C) GA; (D) EG; (E) TA; (F) Podophillotoxin 0.005 µM (positive control); (G) H2O2 apoptosis positive control; (H) Necrosis control. Full article ">Figure 5
Effect of TA, GA and EG on mRNA expression levels of Bcl-2 and Bax in Hep3B cells after 72 h treatment. GAPDH was used as an internal control. Full article ">Figure 6
Caspase 3/7 activity after treatment with GA; EG; TA and taxol (TX) in Hep3B cells. * p < 0.05, ** p < 0.01, *** p < 0.001 were obtained when compared to the negative control. Full article ">

3229 KiB

Open AccessArticle

Development of User-Friendly Method to Distinguish Subspecies of the Korean Medicinal Herb Perilla frutescens Using Multiplex-PCR

by Yonguk Kim, Ah-Young Kim, Ara Jo, Hakjoon Choi, Seung-Sik Cho and Chulyung Choi

Molecules 2017, 22(4), 665; https://doi.org/10.3390/molecules22040665 - 21 Apr 2017

Cited by 9 | Viewed by 5123

Abstract

Perilla (Perilla frutescens) is an economically and culturally important plant in East Asia. Plant breeding between cultivars has enhanced the genetic diversity of perilla overall, but means that functionally diverse subspecies are more difficult to identify and distinguish. In this study, [...] Read more.

Perilla (Perilla frutescens) is an economically and culturally important plant in East Asia. Plant breeding between cultivars has enhanced the genetic diversity of perilla overall, but means that functionally diverse subspecies are more difficult to identify and distinguish. In this study, we developed gene-based DNA markers to distinguish between the Korean herbal medicinal perilla varieties. We identified informative simple sequence repeat (SSR) regions on the promoter regions of the Myb-P1 and dihydroflavonol 4-reductase (DFR) genes, as well as a large insertion-deletion (indel) region in the limonene synthase (LS) gene, and developed markers to characterize the distinct subspecies differences (PfMyb-P1pro, PfDFRpro, and PfLS, respectively). Using the PfLS primers, a 430-bp region could be amplified from P. frutescens var. acuta, crispa, and f. viridis (known as Jasoyeop, Jureum-soyeop, and Chungsoyeop, respectively), but not from P. frutescens var. japonica (Dlggae). The PfMybpro primers resulted in PCR products of 314 or 316, 330, 322, and 315 bp from Dlggae, Jasoyeop, Jureum-soyeop, and Chungsoyeop, respectively, and the PfDFRpro primers resulted in products of 189 or 202, 187 or 189, 185 or 189, and 193bp, respectively, for the four perilla subspecies. Combining these three reactions into a single multiplex PCR approach resulted in subspecies-specific PCR band patterns for six common types of commercial perilla, distinguishing between three varieties of Dlggae (Cham-Dlggae, Ip-Dlggae, and Bora-Dlggae), as well as identifying Jasoyeop, Jureum-soyeop, and Chungsoyeop. These user-friendly markers will be valuable as a simple and efficient method for identifying the Korean medicinal herb Jasoyeop, as well as distinguishing between other functionally distinct subspecies, which may have broad applications in the Korean herbal industry. Full article

(This article belongs to the Section Molecular Diversity)

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Figure 1
Development of the PfLS marker. (a) LS region specific to PA-type genomes identified in P. frutescens var. crispa, acuta, and viridis. The amplified region covered part of exon 4 and 3′ UTR; (b) Application of the PfLS marker in the commercial breeding perilla lines (1–2: P. frutescens var. japonica; 3–5:f. viridis; 6–8: var. acuta; 9–11: var. crispa). (c) 430 bp sites of specific target region. Full article ">Figure 2
Development of the PfMyb-P1pro marker. (a) Identification of a simple sequence repeat (SSR) in the promoter region of the Myb-P1 gene. The sequence alignment shows the SSR variation of the 5′-UTR Py-rich stretch and AT-rich regions in the promoter of Myb-P1 among four subspecies of P. frutescens. The SSR variations are highlighted in green; (b) Application of the PfMyb-P1pro marker in the commercial breeding perilla lines. (M: 100bp DNA ladder; 1–2: P. frutescens var. japonica; 3–5: f. viridis; 6–8: var. acuta Kudo; 9–11: var. crispa). Full article ">Figure 3
Development of the PfDFRpro marker. (a) Identification of a simple sequence repeat (SSR) in the promoter region of the DFR gene. The sequence alignment shows the SSR variation of 5′-UTR Py-rich stretch in the promoter of DFR among four subspecies of P. frutescens. The SSR variations are highlighted in green; (b) Application of the PfDFRpro marker in the commercial breeding perilla lines. (M: 100bp DNA ladder; 1–2: P. frutescens var. japonica; 3–5: var. crispa; 6–8: var. acuta; 9–11:f. viridis). Full article ">Figure 4
Multiplex PCR assay using three specific markers for the perilla subspecies in a single reaction. A mixture of three specific markers, PfLS, PfMyb-P1pro, and PfDFRpro, was used for PCR amplification. Lanes on 3% electrophoresis gel: M: 100 bp DNA ladder; 1–3: ‘Cham-Dlggae’, ‘Ip-Dlggae’, and ‘Bora-Dlggae’, respectively, which represent the three cultivar types of P. frutescens var. japonica; 4: ‘Jureum-soyeop’, representing P. frutescens var. crispa; 5: ‘Jasoyeop’, representing P. frutescens var. acuta; 6: ‘Chungsoyeop’, representing P. frutescens f. viridis. Full article ">Figure 5
Multiplex PCR identification of 11 commercial dried leaves and twigs of Jasoyeop products. (a) Lanes on 3% electrophoresis gel: M: 100 bp DNA ladder; A–K: purchased commercial dried Jasoyeop products (see <a href="#molecules-22-00665-t003" class="html-table">Table 3</a> for full details); (b,c) Sequence analysis of PCR products amplified using the PfMybpro and PfDFRpro marker primers, respectively, aligned using Clustal W2. Full article ">

4311 KiB

Open AccessArticle

Ameliorative Effects and Possible Molecular Mechanism of Action of Black Ginseng (Panax ginseng) on Acetaminophen-Mediated Liver Injury

by Jun-Nan Hu, Zhi Liu, Zi Wang, Xin-Dian Li, Lian-Xue Zhang, Wei Li and Ying-Ping Wang

Molecules 2017, 22(4), 664; https://doi.org/10.3390/molecules22040664 - 21 Apr 2017

Cited by 53 | Viewed by 7865

Abstract

Background: Frequent overdosing of acetaminophen (APAP) has become the major cause of acute liver injury (ALI). The present study aimed to evaluate the potential hepatoprotective effects of black ginseng (BG) on APAP-induced mice liver injuries and the underlying mechanisms of action were [...] Read more.

Background: Frequent overdosing of acetaminophen (APAP) has become the major cause of acute liver injury (ALI). The present study aimed to evaluate the potential hepatoprotective effects of black ginseng (BG) on APAP-induced mice liver injuries and the underlying mechanisms of action were further investigated for the first time. Methods: Mice were treated with BG (300, 600 mg/kg) by oral gavage once a day for seven days. On the 7th day, all mice were treated with 250 mg/kg APAP which caused severe liver injury after 24 h and hepatotoxicity was assessed. Results: Our results showed that pretreatment with BG significantly decreased the levels of serum alanine aminotransferase (ALT) and aspartate transaminase (AST) compared with the APAP group. Meanwhile, hepatic antioxidant including glutathione (GSH) was elevated compared with the APAP group. In contrast, a significant decrease of the levels of the lipid peroxidation product malondialdehyde (MDA) was observed in the BG-treated groups compared with the APAP group. These effects were associated with significant increases of cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) levels in liver tissues. Moreover, BG supplementation suppressed activation of apoptotic pathways through increasing Bcl-2 and decreasing Bax protein expression levels according to western blotting analysis. Histopathological examination revealed that BG pretreatment significantly inhibited APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress like 3-nitrotyrosine (3-NT) were also inhibited after pretreatment with BG, compared with the APAP group. Conclusions: The results clearly suggest that the underlying molecular mechanisms of action of BG-mediated alleviation of APAP-induced hepatotoxicity may involve its anti-oxidant, anti-apoptotic, anti-inflammatory and anti-nitrative effects. Full article

(This article belongs to the Special Issue Current Trends in Ginseng Research)

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HPLC chromatogram of ginsenosides in mixed standard compounds (A) and Black ginseng (B). Full article ">Figure 2
Effects of BG on levels of ALT (A) and AST (B) in serums, and GSH (C) and MDA (D) in liver tissues of mice. Values are expressed as the mean ± S.D., n = 8; ** p < 0.01, * p < 0.05 vs. normal group; # p < 0.05 vs. APAP group. Full article ">Figure 3
Effects of BG on expression of 4-hydroxynonenal (4-HNE) (A), cytochrome P450 E1 (CYP2E1) (B) and 3-nitrotyrosine (3-NT) (C) in liver tissues, and the fluorescence intensities were quantified. The expression levels of 4-HNE, CYP2E1 (green) and 3-NT (red) in tissue section isolated from different groups were assessed by immunofluorescence. Representative immunofluorescence images were taken at 200×. 4,6-Diamidino-2-phenylindole (DAPI) (blue) was used as a nuclear counterstain. All data were expressed as mean ± S.D, n = 8. ** p < 0.01 vs. normal group; ## p < 0.01, # p < 0.05, vs. APAP group. Full article ">Figure 4
Histological examination of morphological changes in liver tissues. Pathological change of livers (A); and liver tissues stained with H&E (B); and Hoechst 33258 (C); and the percentage of apoptosis (D). Arrows show necrotic and injured cells. All data were expressed as mean ± S.D, n = 8. ** p < 0.01 vs. normal group; # p < 0.05, vs. APAP group. Full article ">Figure 5
Effects of BG on the protein expression of Bax; and Bcl-2 (A); and results are quantified from their band intensities (B). The protein expression was examined by western blotting analysis in liver tissues from normal, APAP, APAP + BG (300 mg/kg), and APAP + BG (600 mg/kg) group animals. All data were expressed as mean ± S.D., n = 8. * p < 0.05 vs. normal group; # p < 0.05 vs. APAP group. Full article ">Figure 6
Effects of BG on expression of COX-2 and iNOS in liver tissues. Arrows show necrotic and inflammatory cells. Full article ">

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Open AccessArticle

On the Morphology of Group II Metal Fluoride Nanocrystals at Finite Temperature and Partial Pressure of HF

by Zeinab Kaawar, Stefan Mahn, Erhard Kemnitz and Beate Paulus

Molecules 2017, 22(4), 663; https://doi.org/10.3390/molecules22040663 - 21 Apr 2017

Cited by 4 | Viewed by 4414

Abstract

We have investigated the bulk and surface properties of the group II metal fluorides CaF

_{2}

, SrF

_{2}

and BaF

_{2}

using periodic density functional theory (DFT) calculations and surface thermodynamics. Our bulk results show that the best agreement with experiment is [...] Read more.

We have investigated the bulk and surface properties of the group II metal fluorides CaF

_{2}

, SrF

_{2}

and BaF

_{2}

using periodic density functional theory (DFT) calculations and surface thermodynamics. Our bulk results show that the best agreement with experiment is achieved with the B3LYP and PBE functionals. We determined the relative importance of the low index surfaces in vacuum and found that an fluoride microcrystal exposes only the (111) surface in which the undercoordinated cations are sevenfold coordinated. With methods of ab initio surface thermodynamics, we analyzed the stability of different surfaces under hydrogen fluoride (HF) pressure and determined the presumable shape of the crystals with respect to different HF concentrations and temperatures. In the case of CaF

_{2}

and SrF

_{2}

, the calculated shapes of the crystals agree well with TEM images of fluorolytic sol-gel synthesized nanocrystals at room temperature and high HF concentration. Full article

(This article belongs to the Special Issue Nano-sized Metal Fluorides: Novel Approaches to Lewis Acid Catalysts)

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9169 KiB

Open AccessArticle

Improved Synthesis of 1-O-Acyl-β-d-Glucopyranose Tetraacetates

by Yu Chen, Huan Lu, Yanyu Chen, Wansheng Yu, Hui Dai and Xianhua Pan

Molecules 2017, 22(4), 662; https://doi.org/10.3390/molecules22040662 - 21 Apr 2017

Cited by 2 | Viewed by 4229

Abstract

An improved synthesis of 1-O-acyl glucosyl esters that avoids the use of expensive Ag reagents as well as the hydrolysis of unstable glucosyl bromides is reported. Notably, β-configuration products were obtained exclusively in good yields. Full article

(This article belongs to the Section Organic Chemistry)

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4159 KiB

Open AccessArticle

Evaluation of Tanshinone IIA Developmental Toxicity in Zebrafish Embryos

by Tao Wang, Chengxi Wang, Qiong Wu, Kangdi Zheng, Jiaojiao Chen, Yutao Lan, Yao Qin, Wenjie Mei and Baoguo Wang

Molecules 2017, 22(4), 660; https://doi.org/10.3390/molecules22040660 - 21 Apr 2017

Cited by 37 | Viewed by 6308

Abstract

Tanshinone IIA (Tan-IIA) is derived from the dried roots of Salvia miltiorrhiza Bunge, a traditional Chinese medicine. Although Salvia miltiorrhiza has been applied for many years, the toxicity of the mono-constituent of Salvia miltiorrhiza, tanshinone IIA, is still understudied. This study evaluated [...] Read more.

Tanshinone IIA (Tan-IIA) is derived from the dried roots of Salvia miltiorrhiza Bunge, a traditional Chinese medicine. Although Salvia miltiorrhiza has been applied for many years, the toxicity of the mono-constituent of Salvia miltiorrhiza, tanshinone IIA, is still understudied. This study evaluated the cardiotoxicity and developmental malformations of Tan-IIA by using zebrafish normal embryos and dechorionated embryos. After treatment with Tan-IIA in different concentrations for four-day periods, obvious pericardial edema, spinal curvature, and even missing tails were observed in zebrafish embryos. The LC₅₀ values in the dechorionated embryo group at 72 h post-fertilization (hpf) and 96 hpf were 18.5 μM and 12.8 μM, respectively, and the teratogenicity was manifested at a concentration of about 1 µM. The main endpoints of teratogenicity were scoliosis, malformation of tail, and pericardium edema. Our findings displayed the potential cardiotoxicity and severe impact on the abnormal development of Tan-IIA in zebrafish embryo at high concentrations, which may help avoid the risk of its clinical application. Full article

(This article belongs to the Special Issue ECSOC-20)

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521 KiB

Open AccessArticle

Synthesis and Antiviral Activity of Novel 1,4-Pentadien-3-one Derivatives Containing a 1,3,4-Thiadiazole Moiety

by Lu Yu, Xiuhai Gan, Dagui Zhou, Fangcheng He, Song Zeng and Deyu Hu

Molecules 2017, 22(4), 658; https://doi.org/10.3390/molecules22040658 - 21 Apr 2017

Cited by 48 | Viewed by 5970

Abstract

1,4-Pentadien-3-one derivatives derived from curcumin possess excellent inhibitory activity against plant viruses. On the basis of this finding, a series of novel 1,4-pentadien-3-one derivatives containing a 1,3,4-thiadiazole moiety were designed and synthesized, and their structures confirmed by IR, ¹H-NMR, and ¹³C-NMR [...] Read more.

1,4-Pentadien-3-one derivatives derived from curcumin possess excellent inhibitory activity against plant viruses. On the basis of this finding, a series of novel 1,4-pentadien-3-one derivatives containing a 1,3,4-thiadiazole moiety were designed and synthesized, and their structures confirmed by IR, ¹H-NMR, and ¹³C-NMR spectroscopy and elemental analysis. The antiviral activities of the title compounds were evaluated against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) in vivo. The assay results showed that most of compounds had remarkable antiviral activities against TMV and CMV, among which compounds 4b, 4h, 4i, 4k, 4o, and 4q exhibited good curative, protection, and inactivation activity against TMV. Compounds 4h, 4i, 4k, 4l, 4o, and 4q exhibited excellent protection activity against TMV, with EC₅₀ values of 105.01, 254.77, 135.38, 297.40, 248.18, and 129.87 μg/mL, respectively, which were superior to that of ribavirin (457.25 µg/mL). In addition, preliminary SARs indicated that small electron-withdrawing groups on the aromatic ring were favorable for anti-TMV activity. This finding suggests that 1,4-pentadien-3-one derivatives containing a 1,3,4-thiadiazole moiety may be considered as potential lead structures for discovering new antiviral agents. Full article

(This article belongs to the Special Issue Frontiers in Antimicrobial Drug Discovery and Design)

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3615 KiB

Open AccessArticle

Synthesis and Self-Assembly of Shape Amphiphiles Based on POSS-Dendron Conjugates

by Yu Shao, Minyuan Ding, Yujie Xu, Fangjia Zhao, Hui Dai, Xia-Ran Miao, Shuguang Yang and Hui Li

Molecules 2017, 22(4), 622; https://doi.org/10.3390/molecules22040622 - 21 Apr 2017

Cited by 8 | Viewed by 7085

Abstract

Shape has been increasingly recognized as an important factor for self-assembly. In this paper, a series of shape amphiphiles have been built by linking polyhedral oligomeric silsesquioxane (POSS) and a dendron via linkers of different lengths. Three conjugates of octahedral silsesquioxanes (T₈ [...] Read more.

Shape has been increasingly recognized as an important factor for self-assembly. In this paper, a series of shape amphiphiles have been built by linking polyhedral oligomeric silsesquioxane (POSS) and a dendron via linkers of different lengths. Three conjugates of octahedral silsesquioxanes (T₈-POSS) and dendron are designed and synthesized and are referred to as isobutyl T₈-POSS gallic acid derivatives (BPOSS-GAD-1, BPOSS-GAD-2, BPOSS-GAD-3). These samples have been fully characterized by ¹H-NMR, ¹³C-NMR, Fourier transform infrared (FT-IR) spectroscopy and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry to establish their chemical identity and purity. Driven by different interactions between POSS and dendron, ordered superstructure can be found upon self-assembly. The stabilities and structures of these samples are further studied by using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and molecular simulations. The results show that their melting points range from 74 °C to 143 °C and the molecular packing schemes in the assemblies can form lamellar structure of BPOSS-GAD-3 as determined by the different linkers. Full article

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Full article ">Figure 1
1H-NMR spectra of BPOSS-GAD-1 (A), BPOSS-GAD-2 (B) and BPOSS-GAD-3 (C). Asterisk (*) represents the resonances from the residual proton signals from CDCl3. Full article ">Figure 1 Cont.
1H-NMR spectra of BPOSS-GAD-1 (A), BPOSS-GAD-2 (B) and BPOSS-GAD-3 (C). Asterisk (*) represents the resonances from the residual proton signals from CDCl3. Full article ">Figure 2
DSC curves of BPOSS-GAD-1 (black line), BPOSS-GAD-2 (red line) and BPOSS-GAD-3 (blue line). Full article ">Figure 3
SAXS (a) and WAXD (b) curves of BPOSS-GAD-1 (lack line), BPOSS-GAD-2 (red line) and BPOSS-GAD-3 (blue line). Full article ">Figure 4
Possible model for the molecular packing scheme of BPOSS-GAD-3 in the lamellae superlattice: (a) xy-plane when projected from z-axis; (b) yz-plane when projected from x-axis; (c) xz-plane when projected from y-axis. Full article ">Scheme 1
Synthesis route of the target shape amphiphiles. Full article ">

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Open AccessReview

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy

by Cassiano Felippe Gonçalves-de-Albuquerque, Adriana Ribeiro Silva, Camila Ignácio da Silva, Hugo Caire Castro-Faria-Neto and Patrícia Burth

Molecules 2017, 22(4), 578; https://doi.org/10.3390/molecules22040578 - 21 Apr 2017

Cited by 56 | Viewed by 28476

Abstract

Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is [...] Read more.

Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy. Full article

(This article belongs to the Special Issue Cardiotonic Steroids)

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Figure 1
Scheme of the insertion of Na/K-ATPase into the plasma membrane. Ionic transport is accomplished by ATP hydrolysis and also depends on the physiological concentrations of the ions inside and outside the cell. The α-subunits (with sites for Na, K, ATP, and cardiac glycosides: OUA (ouabain)), β-subunits (glycoprotein) and γ subunits are shown. Full article ">Figure 2
Schematic representation of the subunit domains of Na/K-ATPase, which is composed of a catalytic α-subunit (blue), a glycosylated β-subunit (grey), and, in some tissues, a single transmembrane span containing an extracellular invariant FXYD sequence (green). Full article ">Figure 3
Functions of Na/K-ATPase enzymes in normal and cancer cells and their interaction with cardiotonic steroids. In normal cells, this pump is responsible for several functions, such as maintenance of ion homeostasis; maintenance of epithelial cell polarity; participation in the process of cell adhesion; control of cell differentiation and proliferation and maintenance of muscular tone. Its interaction with cardiotonic steroids results in enzymatic inhibition; Ca2+ intracellular accumulation; activation of caspases; control of muscle tone; cell growth, proliferation, adhesion and survival via signalling pathways. In cancer cells, there are several changes in Na/K-ATPase that result in ionic disorder; enzymatic down- or up-regulation of expression; loss of epithelial cell polarity and cell adhesion; changes in cell differentiation and proliferation. Interaction with cardiotonic steroids may result in inhibition; activation of protein cascade; apoptosis; autophagy; production of inflammatory mediators; reactive oxygen species (ROS) generation and cell cycle arrest. Most of these phenomena are linked to intracellular signalling mediated by the enzyme. Full article ">Figure 4
Structure of the alveolar–capillary barrier in the intact lung and Na/K-ATPase signalosome. Alveolar type I and II cells form the alveolar barrier and present the Na+ channel, Na/K-ATPase (NKA) and aquaporin 5. Endothelial cells form the capillary wall (A); Signalosome of Na/K-ATPase (B); Binding of cardiotonic steroids to Na/K-ATPase triggers a cascade of events starting with activation and phosphorylation of Src and caveolin-1, which leads to the transactivation of the epidermal growth factor receptor (EGFR). Activation of the Ras-Raf-MAPK cascade increases cytoplasmic Ca2+ and activates the production of reactive oxygen species (ROS) by the mitochondria. Augmented Ca2+ activates NFκB, leading to immune system activation, cellular proliferation or apoptosis. Other recruited proteins include PLC (not shown) and PI3K. The downstream effects are various and include inhibition of the cytoprotective effects of NF-kB and Akt and the activation of AP-1 and Erk1/2, leading eventually to cell death via apoptosis and autophagy. However, the type of response depends on the cell type, glycoside concentration and exposure time. ENaC—Epithelial sodium channel; CFTR—Cystic fibrosis transmembrane conductance regulator; EGFR—Epidermal growth factor receptor; NFκB—Nuclear factor kappa-light-chain-enhancer of activated B cells; PLC—Phospholipase C; PI3K—Phosphoinositide 3-kinase; Akt—Protein kinase B; AP-1—Activator protein 1; Erk—Extracellular signal-regulated kinases. Full article ">

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Open AccessArticle

Reactions of 5-Indolizyl Lithium Compounds with Some Bielectrophiles

by Sergey A. Rzhevskii, Victor B. Rybakov, Victor N. Khrustalev and Eugene V. Babaev

Molecules 2017, 22(4), 661; https://doi.org/10.3390/molecules22040661 - 20 Apr 2017

Cited by 4 | Viewed by 5845

Abstract

Abstract: Indolizyl-5-lithium anions react with succinic and phtalic anhidrides giving 1,4-keto acids, with oxallyl chloride giving 1,2-diketone, and with ethyl pyruvate giving 1,2-hydroxyacid. However, with α-halocarbonyl compounds, they react in different ways, forming the products of selective bromination at C-5 (with α-bromo [...] Read more.

Abstract: Indolizyl-5-lithium anions react with succinic and phtalic anhidrides giving 1,4-keto acids, with oxallyl chloride giving 1,2-diketone, and with ethyl pyruvate giving 1,2-hydroxyacid. However, with α-halocarbonyl compounds, they react in different ways, forming the products of selective bromination at C-5 (with α-bromo ketones and esters of α-bromo acids) and 5-chloroacetyl indolizines. Full article

(This article belongs to the Collection Heterocyclic Compounds)

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3158 KiB

Open AccessArticle

Synthesis, Biological Evaluation, and Molecular Docking Studies of Novel Isatin-Thiazole Derivatives as α-Glucosidase Inhibitors

by Zhenzhen Xie, Guangcheng Wang, Jing Wang, Ming Chen, Yaping Peng, Luyao Li, Bing Deng, Shan Chen and Wenbiao Li

Molecules 2017, 22(4), 659; https://doi.org/10.3390/molecules22040659 - 20 Apr 2017

Cited by 45 | Viewed by 6029

Abstract

A series of novel isatin-thiazole derivatives were synthesized and screened for their in vitro α-glucosidase inhibitory activity. These compounds displayed a varying degree of α-glucosidase inhibitory activity with IC₅₀ ranging from 5.36 ± 0.13 to 35.76 ± 0.31 μm as compared to [...] Read more.

A series of novel isatin-thiazole derivatives were synthesized and screened for their in vitro α-glucosidase inhibitory activity. These compounds displayed a varying degree of α-glucosidase inhibitory activity with IC₅₀ ranging from 5.36 ± 0.13 to 35.76 ± 0.31 μm as compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μm). Among the series, compound 6p bearing a hydroxyl group at the 4-position of the right phenyl and 2-fluorobenzyl substituent at the N1-positions of the 5-methylisatin displayed the highest inhibitory activity with an IC₅₀ value of 5.36 ± 0.13 μm. Molecular docking studies revealed the existence of hydrophobic interaction, CH-π interaction, arene-anion interaction, arene-cation interaction, and hydrogen bond between these compounds and α-glucosidase enzyme. Full article

(This article belongs to the Section Medicinal Chemistry)

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Full article ">Figure 1
The chemical structures of the reported α-glucosidase inhibitors containing isatin or thiazole moiety. Full article ">Figure 2
Compound 6i (A) and acarbose (B) was docked to the binding pocket of the Saccharomyces cerevisiae α-glucosidase. Full article ">Figure 3
(A) Compound 6p was docked to the binding pocket of the Saccharomyces cerevisiae α-glucosidase. (B) Compounds 6i and 6p were docked to the binding pocket of the Saccharomyces cerevisiae α-glucosidase (overlapped). Full article ">Figure 4
(A) Compound 6b was docked to the binding pocket of the Saccharomyces cerevisiae α-glucosidase. (B) Compounds 6b and 6p were docked to the binding pocket of the Saccharomyces cerevisiae α-glucosidase (overlapped). Full article ">Scheme 1
Reagents and conditions: (a) R2X, K2CO3, DMF, room temperature, 2 h; (b) EtOH, 45 °C, 3 h; (c) p-MeC6H4SO3H, NBS, CH3CN, reflux, 2 h; (d) EtOH, reflux, 2 h. Full article ">

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Open AccessArticle

Diversity Analysis and Bioresource Characterization of Halophilic Bacteria Isolated from a South African Saltpan

by Ramganesh Selvarajan, Timothy Sibanda, Memory Tekere, Hlengilizwe Nyoni and Stephen Meddows-Taylor

Molecules 2017, 22(4), 657; https://doi.org/10.3390/molecules22040657 - 20 Apr 2017

Cited by 36 | Viewed by 9126

Abstract

Though intensive research has been channeled towards the biotechnological applications of halophiles and other extremophilic microbes, these studies have not been, by any means, exhaustive. Saline environments still offer a vast diversity of microbes with potential to produce an array of natural products [...] Read more.

Though intensive research has been channeled towards the biotechnological applications of halophiles and other extremophilic microbes, these studies have not been, by any means, exhaustive. Saline environments still offer a vast diversity of microbes with potential to produce an array of natural products which can only be unlocked by concerted research efforts. In this study, a combination of culture and molecular approaches were employed to characterize halophilic bacteria from saltpan water samples and profile their potential biotechnological applications. Physicochemical analysis of the water samples showed that pH was alkaline (pH 8.8), with a salinity of 12.8%. 16S rRNA gene targeted amplicon analysis produced 10 bacterial phyla constituting of Bacteroidetes (30.57%), Proteobacteria (15.27%), Actinobacteria (9.05%), Planctomycetes (5.52%) and Cyanobacteria (3.18%). Eighteen strains were identified using sequencing analysis of the culturable bacterial strains. From these, the strains SP7 and SP9 were positive for cellulase production while the strains SP4, SP8 and SP22 were positive for lipase production. Quantitative enzyme assays showed moderate extracellular cellulase activity (1.95 U/mL) and lipase activity (3.71 U/mL) by the isolate SP9 and SP4 respectively. Further, of the six isolates, the isolate SP9 exhibited exploitable potential in the bioremediation of hydrocarbon pollution as demonstrated by its fairly high activity against benzanthracene (70% DCPIP reduction). Elucidation of the isolates secondary metabolites showed the production of the molecules 2,3-butanediol, hexahydro-3-(2-methylpropyl)pyrrole[1,2a]pyrazine-1,4-dione, aziridine, dimethylamine and ethyl acetate (GC-MS) and oxypurinol and 5-hydroxydecanoic acid (LC-MS), particularly by the isolate Salinivibrio sp. SP9. Overall, the study showed that the isolated halophiles can produce secondary metabolites with potential industrial and pharmaceutical application. Full article

(This article belongs to the Collection Phytochemicals: Biosynthesis, Metabolism and Biological Activities)

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10429 KiB

Open AccessArticle

Study on the Rationality for Antiviral Activity of Flos Lonicerae Japonicae-Fructus Forsythiae Herb Couple Preparations Improved by Chito-Oligosaccharide via Integral Pharmacokinetics

by Wei Zhou, Ailing Yin, Jinjun Shan, Shouchuan Wang, Baochang Cai and Liuqing Di

Molecules 2017, 22(4), 654; https://doi.org/10.3390/molecules22040654 - 20 Apr 2017

Cited by 32 | Viewed by 5812

Abstract

In the present study, the rationality for the antiviral effect (H1N1 virus) of Flos Lonicerae Japonicae (FLJ, named JinYinHua)-Fructus forsythiae (FF, named LianQiao) herb couple preparations improved by chito-oligosaccharide (COS) was investigated. We found that the improvement of antiviral activity for four preparations [...] Read more.

In the present study, the rationality for the antiviral effect (H1N1 virus) of Flos Lonicerae Japonicae (FLJ, named JinYinHua)-Fructus forsythiae (FF, named LianQiao) herb couple preparations improved by chito-oligosaccharide (COS) was investigated. We found that the improvement of antiviral activity for four preparations attributed to the enhancement of bioavailability for the FLJ-FF herb couple in vivo, and that caffeic acid derivatives are the most important type of components for antiviral activity. The anti-Influenza virus activity-half maximal inhibitory concentration (IC₅₀), not area under concentration (AUC) was considered as the weighting factor for integrating the pharmacokinetics of caffeic acid derivatives. It was found that the integral absorption, both in vitro and in vivo, especially that in Shuang-Huang-Lian, can be improved significantly by COS, an absorption enhancer based on tight junction. The results indicated that the antiviral activity in four preparations improved by COS was mainly attributed to the integral absorption enhancement of caffeic acid derivatives. Full article

(This article belongs to the Section Natural Products Chemistry)

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Full article ">Figure 1
Chemical structure of COS. Full article ">Figure 2
Chemical structure of caffeic acid derivatives. Full article ">Figure 3
Effect of Shuang-Huang-Lian groups (A, A1, A2, A3 and A4), Yin-Qiao-Jie-Du groups (B, B1, B2, B3 and B4), Fufang Qin-Lan groups (C, C1, C2, C3 and C4) and Qin-Re-Jie-Du groups (D, D1, D2, D3 and D4) on influenza virus. (*) p < 0.05 and (**) p < 0.01, compared with the A, B, C and D groups, respectively (Mean ± SD, n = 6). Full article ">Figure 4
Effect of caffeic acid derivatives of different concentrations on the influenza virus. Inhibition rate was assayed with MTT and expressed as a percentage of controls (Mean ± SD, n = 8). Full article ">Figure 5
Integral pharmacokinetic parameters (AUC0–24h) and antiviral efficacy (AUE0–24h) of caffeic acid derivatives in the FLJ-FF herb couple knocked or without knocked in forsythoside A. (*) p < 0.05 compared with the control group. (A1,A2) represent integral mean pharmacokinetic profiles and AUC0–24h based on AUC, respectively; (B1,B2) represent integral mean pharmacokinetic profiles and AUC0–24h based on IC50, respectively; (C1,C2) represent mean inhibition profiles and AUE0–24h, respectively; (D) represents the correlation between integral AUC0–24h based on IC50 and AUE0–24h after the concentration of forsythoside A gradually knocked in the FLJ-FF herb couple (Mean ± SD, n = 6). Full article ">Figure 6
Effect of COS on the integral Papp-value of caffeic acid derivatives in Caco-2 cell in vitro model. (**) p < 0.01, compared with control group. (Mean ± SD, n = 3). Full article ">Figure 7
Effect of COS on the integral pharmacokinetic profiles of caffeic acid derivative following oral administration of the FLJ-FF herb couple preparations. ((A) Shuang-Huang-Lian extract; (B) Yin-Qiao-Jie-Du extract; (C) Fufang Qin-Lan extract; (D) Qin-Re-Jie-Du extract) (Mean ± SD, n = 6). Full article ">

8629 KiB

Open AccessArticle

Gamma-Aminobutyric Acid Increases the Production of Short-Chain Fatty Acids and Decreases pH Values in Mouse Colon

by Min Xie, Hai-Hong Chen, Shao-Ping Nie, Jun-Yi Yin and Ming-Yong Xie

Molecules 2017, 22(4), 653; https://doi.org/10.3390/molecules22040653 - 20 Apr 2017

Cited by 23 | Viewed by 6082

Abstract

Gamma-Aminobutyric acid (GABA) could regulate physiological functions in the gastrointestinal tract. The present study aimed to investigate the effect of GABA on colon health in mice. The female Kunming mice were given GABA at doses of 5, 10, 20 and 40 mg/kg/d for [...] Read more.

Gamma-Aminobutyric acid (GABA) could regulate physiological functions in the gastrointestinal tract. The present study aimed to investigate the effect of GABA on colon health in mice. The female Kunming mice were given GABA at doses of 5, 10, 20 and 40 mg/kg/d for 14 days. Afterwards, the short-chain fatty acids (SCFAs) concentrations, pH values, colon index, colon length and weight of colonic and cecal contents were determined to evaluate the effects of GABA on colon health. The results showed that intake of GABA could increase the concentrations of acetate, propionate, butyrate and total SCFAs in colonic and cecal contents, as well as the weight of colonic and cecal contents. The colon index and length of the 40 mg/kg/d GABA-treated group were significantly higher than those of the control group (p < 0.05). In addition, decrease of pH values in colonic and cecal contents was also observed. These results suggest that GABA may improve colon health. Full article

(This article belongs to the Section Medicinal Chemistry)

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Full article ">Figure 1
The colon index (A) and colon length (B) of mice treated with gamma-Aminobutyric acid (GABA). Results are expressed as mean value ± SD (n = 12). Data with different letters in the same column means significant difference among groups (p < 0.05). Colon index was calculated by using Equation (1). Full article ">Figure 2
The weight of colonic (A) and cecal (B) contents of mice treated with GABA. Result are expressed as means value ± SD (n = 12). Data with different letters in the same column means significant difference among groups (p < 0.05). Full article ">Figure 3
pH values change in colonic (A) and cecal contents (B) of mice treated with GABA. The results were expressed as mean ± SD (n = 12), and evaluated by one way ANOVA with turkey test. Values with different letters indicated significant different among groups (p < 0.05). Full article ">Figure 4
The effect of GABA on total short-chain fatty acid (SCFA) concentrations in the mice colonic (A) and cecal (B) contents. Data was represented as mean ± SD (n = 12), and evaluated by one way ANOVA with turkey test. Values with different letters expressed significant differences among groups (p < 0.05). Full article ">Figure 5
The effect of GABA on individual SCFA concentration in the mice colonic content, acetic acid (A), propionic acid (B), n-butyric acid (C), isobutyric acid (D), n-valeric acid (E), isovaleric acid (F), respectively The data was presented as mean ± SD (n = 12), and evaluated by one way ANOVA with turkey test. Values with different letters in the same chart indicated significant differences among groups (p< 0.05). Full article ">Figure 5 Cont.
The effect of GABA on individual SCFA concentration in the mice colonic content, acetic acid (A), propionic acid (B), n-butyric acid (C), isobutyric acid (D), n-valeric acid (E), isovaleric acid (F), respectively The data was presented as mean ± SD (n = 12), and evaluated by one way ANOVA with turkey test. Values with different letters in the same chart indicated significant differences among groups (p< 0.05). Full article ">Figure 6
The effect of GABA on individual SCFA in the mice cecal content, acetic acid (A), propionic acid (B), n-butyric acid (C), isobutyric acid (D), n-valeric acid (E), isovaleric acid (F), respectively. Data was expressed as mean ± SD (n = 12), and evaluated by one way ANOVA with turkey test. Results with different letters showed significant differences from each group (p < 0.05). Full article ">

4022 KiB

Open AccessArticle

Modification of Natural Eudesmane Scaffolds via Mizoroki-Heck Reactions

by Mohamed Zaki, Mohamed Akssira and Sabine Berteina-Raboin

Molecules 2017, 22(4), 652; https://doi.org/10.3390/molecules22040652 - 20 Apr 2017

Viewed by 5024

Abstract

The Mizoroki-Heck reaction was applied to substrates derived from isocostic and ilicic acids, important sesquiterpene components of Dittrichia viscosa L. Greuter that were extracted directly from plant material collected in Morocco. After optimization of the metallo-catalysis conditions, various aryl-groups were successfully introduced on [...] Read more.

The Mizoroki-Heck reaction was applied to substrates derived from isocostic and ilicic acids, important sesquiterpene components of Dittrichia viscosa L. Greuter that were extracted directly from plant material collected in Morocco. After optimization of the metallo-catalysis conditions, various aryl-groups were successfully introduced on the exocyclic double bond with an exclusive E-configuration and without racemization. Full article

(This article belongs to the Collection Bioactive Compounds)

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708 KiB

Open AccessReview

The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases

by Yu-Ping Jia, Lei Sun, He-Shui Yu, Li-Peng Liang, Wei Li, Hui Ding, Xin-Bo Song and Li-Juan Zhang

Molecules 2017, 22(4), 610; https://doi.org/10.3390/molecules22040610 - 20 Apr 2017

Cited by 90 | Viewed by 22005

Abstract

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular [...] Read more.

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions. Full article

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5249 KiB

Open AccessArticle

Synthetic Fluororutaecarpine Inhibits Inflammatory Stimuli and Activates Endothelial Transient Receptor Potential Vanilloid-Type 1

by Chi-Ming Lee, Jiun-An Gu, Tin-Gan Rau, Chi Wang, Chiao-Han Yen, Shih-Hao Huang, Feng-Yen Lin, Chun-Mao Lin and Sheng-Tung Huang

Molecules 2017, 22(4), 656; https://doi.org/10.3390/molecules22040656 - 19 Apr 2017

Cited by 11 | Viewed by 4640

Abstract

The natural product, rutaecarpine (RUT), is the main effective component of Evodia rutaecarpa which is a widely used traditional Chinese medicine. It has vasodilation, anticoagulation, and anti-inflammatory activities. However, further therapeutic applications are limited by its cytotoxicity. Thus, a derivative of RUT, 10-fluoro-2-methoxyrutaecarpine [...] Read more.

The natural product, rutaecarpine (RUT), is the main effective component of Evodia rutaecarpa which is a widely used traditional Chinese medicine. It has vasodilation, anticoagulation, and anti-inflammatory activities. However, further therapeutic applications are limited by its cytotoxicity. Thus, a derivative of RUT, 10-fluoro-2-methoxyrutaecarpine (F-RUT), was designed and synthesized that showed no cytotoxicity toward RAW264.7 macrophages at 20 μM. In an anti-inflammation experiment, it inhibited the production of nitric oxide (NO) and tumor necrosis factor (TNF)-α in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages; cyclooxygenase (COX)-2 and inducible NO synthase (iNOS) induced by LPS were also downregulated. After 24 h of treatment, F-RUT significantly inhibited cell migration and invasion of ovarian A2780 cells. Furthermore, F-RUT promoted expressions of transient receptor potential vanilloid type 1 (TRPV1) and endothelial (e)NOS in human aortic endothelial cells, and predominantly reduced the inflammation in ovalbumin/alum-challenged mice. These results suggest that the novel synthetic F-RUT exerts activities against inflammation and vasodilation, while displaying less toxicity than its lead compound. Full article

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Full article ">Figure 1
Effects of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on nitric oxide (NO) and tumor necrosis factor (TNF)-α release by lipopolysaccharide (LPS)-treated (40 ng/mL) RAW264.7 macrophages. (a) NO levels were detected in culture medium using the Griess reaction; (b) TNF-α release in cell supernatants was detected using a mouse TNF-α Quantikine kit; (c) Cell viability upon F-RUT and rutaecarpine (RUT) treatment for 24 h in an MTT assay. Values are expressed as the mean ± SE. * p < 0.05, ** p < 0.01. Full article ">Figure 1 Cont.
Effects of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on nitric oxide (NO) and tumor necrosis factor (TNF)-α release by lipopolysaccharide (LPS)-treated (40 ng/mL) RAW264.7 macrophages. (a) NO levels were detected in culture medium using the Griess reaction; (b) TNF-α release in cell supernatants was detected using a mouse TNF-α Quantikine kit; (c) Cell viability upon F-RUT and rutaecarpine (RUT) treatment for 24 h in an MTT assay. Values are expressed as the mean ± SE. * p < 0.05, ** p < 0.01. Full article ">Figure 2
Effect of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions by lipopolysaccharide (LPS)-treated RAW264.7 macrophages (a), and luciferase reporter plasmid-transfected macrophages (b). Cells were transfected with 2.5 μg of the pGL4.32 [luc2P/NF-κB-RE/Hygro] reporter plasmid, then treated with different concentrations of F-RUT and LPS (40 ng/mL) for 24 h. Levels of luciferase activity were determined as described in Materials and Methods. Values are expressed as the mean ± SE of triplicate tests. * p < 0.05, ** p < 0.01 versus LPS treatment. Full article ">Figure 3
Effects of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on migration and invasion. Cell migration (a) and cell invasion (b) were detected following F-RUT treatment for 0–24 h, and photographed with a microscope (upper panel). The statistical analysis is shown in the lower panel. (* p < 0.05, ** p < 0.01). Full article ">Figure 4
Effects of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on transient receptor potential vanilloid-type 1 (TRPV-1) expression and endothelial nitric oxide synthase (eNOS) phosphorylation in human aortic endothelial cells (HAECs). The densitometric ratio is indicated. Full article ">Figure 5
Effects of 10-fluoro-2-methoxyrutaecarpine (F-RUT) on ovalbumin (OVA)-challenged mice. Data are representative of three to five mice per group. Scale bar is 100 µm. Full article ">Scheme 1
Synthesis of 10-fluoro-2-methoxyrutaecarpine (F-RUT) and 10-fluoro-2,3-dimethoxyrutaecarpine. Full article ">

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Open AccessArticle

Protein Stability and Unfolding Following Glycine Radical Formation

by Michael C. Owen,, Imre G. Csizmadia, Béla Viskolcz and Birgit Strodel

Molecules 2017, 22(4), 655; https://doi.org/10.3390/molecules22040655 - 19 Apr 2017

Cited by 6 | Viewed by 5643

Abstract

Glycine (Gly) residues are particularly susceptible to hydrogen abstraction; which results in the formation of the capto-dative stabilized C_α-centered Gly radical (GLR) on the protein backbone. We examined the effect of GLR formation on the structure of the Trp cage; tryptophan [...] Read more.

Glycine (Gly) residues are particularly susceptible to hydrogen abstraction; which results in the formation of the capto-dative stabilized C_α-centered Gly radical (GLR) on the protein backbone. We examined the effect of GLR formation on the structure of the Trp cage; tryptophan zipper; and the villin headpiece; three fast-folding and stable miniproteins; using all-atom (OPLS-AA) molecular dynamics simulations. Radicalization changes the conformation of the GLR residue and affects both neighboring residues but did not affect the stability of the Trp zipper. The stability of helices away from the radical center in villin were also affected by radicalization; and GLR in place of Gly15 caused the Trp cage to unfold within 1 µs. These results provide new evidence on the destabilizing effects of protein oxidation by reactive oxygen species. Full article

(This article belongs to the Special Issue Biomolecular Simulations)

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Figure 1
Cartoon representations of the NMR structures of the Trp cage (protein data bank [PDB] code 1L2Y), Trp zipper (PDB code 1LE0), and villin headpiece (PDB code 1YRF). The interacting Tyr3, Trp6 and Pro19 residues are shown in blue, whereas Asp9, Arg16 (shown in red) and the connected salt bridge (dashed line) are also shown. The two leafs of the β-sheet are shown in yellow and the connecting β-hairpin of the Trp zipper is shown in cyan. The residues that form the hydrophobic core of the villin headpiece are shown in black. Full article ">Figure 2
The central structure of the largest cluster in Trp cage Cα-centered Gly radical in place of Gly10 (GLR10) (in red, A), Trp cage(GLR11) (in blue, B), Trp cage (GLR15) (in green, C), Trp zipper(GLR6) (in red, D), villin(GLR11) (in red, E), and villin(GLR33) (in blue, F). Proteins are aligned with those of their respective closed-shell proteins (in black). The root-mean-squared deviation (RMSD) values of the alignment is shown, whereas the RMSD of each representative structure from the respective starting structure is shown in parentheses. Those of the closed-shell Trp cage, villin, and Trp zipper are 0.86 Å, 0.50 Å, and 2.60 Å, respectively. The residue containing the radical center is shown in the licorice representation, with the radical center represented by a black dot. Full article ">Figure 3
The aligned structures of the each GLR residue of the radicalized protein and its corresponding Gly residue in the respective closed-shell protein. The unpaired electron of the radical center (shown with a dot in the key) is delocalized due to its location between two amide bonds. The atoms with a positive sign (+) belong to the neighboring residue towards the N-terminus, whereas those with a negative sign (−) belong to the neighboring residues towards the C-terminus. The curly arrows indicate the rotated bonds of the φ and Ψ torsional angles. Full article ">Figure 4
The frequency of secondary structure occurrence at each residue of the closed-shell and radicalized Trp cage, Trp zipper and villin headpiece after 100 ns (A) and 1 µs (B). Full article ">Figure 5
The φ and Ψ density plots for (A): Gly10, (B): Gly11, (C): Gly15 and containing Gly radicals (GLR) at their respective Gly positions (A′, B′, and C′) of Trp cage; (D): Gly6 and (D′): GLR6 of Trp zipper; along with (E): Gly11, (F): Gly33 and the respective radicals, (E′) and (F′) of the villin headpiece. As a reference, the areas of the surface that correspond to the α-helix (αL) and β-sheet (β), position two of the classic (γL) and inverted (γL′) γ-turns and position three of type-one (I) and type-two (II) β-turns are are also labeled. Full article ">Figure 6
The backbone RMSD as a function of time of the closed-shell and radicalized Trp cage, Trp zipper and villin headpiece. Full article ">Figure 7
The final structure of Trp cage(GLR10) (in red, A), Trp cage(GLR11) (in blue, B), Trp cage(GLR15) (in green, C), Trp zipper(GLR6) (in red, D), villin(GLR11) (in red, E), and villin(GLR33) (in blue, F). Proteins are aligned with those of their respective closed-shell proteins (in black). The RMSD values of the alignment are shown, whereas the RMSD of each representative structure from the respective starting structure is shown in parentheses. Those of the closed-shell Trp cage, villin, and Trp zipper are 3.885 Å, 1.044 Å, and 4.248 Å, respectively. The residue containing the radical center is shown in the licorice representation, with the radical center. Full article ">Figure 8
The final structure of the Trp cage-wt (in black, A) Trp cage(GLR10) (in red, B), Trp cage(GLR11) (in blue, C), Trp cage(GLR15) (in green, D). The hydrophobic pocket formed by Tyr3, Trp6, and Pro18 remains intact in Trp cage-wt, Trp cage(GLR10), and Trp cage(GLR11), but not in Trp cage(GLR15). The salt bridge between residues Asp9 and Arg16 remains intact in Trp cage-wt and Trp cage(GLR15) but not in Trp cage(GLR10) and in Trp cage(GLR11). Full article ">

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Open AccessArticle

Antifungal and Anti-Biofilm Activities of Acetone Lichen Extracts against Candida albicans

by Marion Millot, Marion Girardot, Lucile Dutreix, Lengo Mambu and Christine Imbert

Molecules 2017, 22(4), 651; https://doi.org/10.3390/molecules22040651 - 19 Apr 2017

Cited by 42 | Viewed by 7764

Abstract

Candida albicans is a commensal coloniser of the human gastrointestinal tract and an opportunistic pathogen, especially thanks to its capacity to form biofilms. This lifestyle is frequently involved in infections and increases the yeast resistance to antimicrobials and immune defenses. In this context, [...] Read more.

Candida albicans is a commensal coloniser of the human gastrointestinal tract and an opportunistic pathogen, especially thanks to its capacity to form biofilms. This lifestyle is frequently involved in infections and increases the yeast resistance to antimicrobials and immune defenses. In this context, 38 lichen acetone extracts have been prepared and evaluated for their activity against C. albicans planktonic and sessile cells. Minimum inhibitory concentrations of extracts (MICs) were determined using the broth microdilution method. Anti-biofilm activity was evaluated using tetrazolium salt (XTT) assay as the ability to inhibit the maturation phase (anti-maturation) or to eradicate a preformed 24 h old biofilm (anti-biofilm). While none of the extracts were active against planktonic cells, biofilm maturation was limited by 11 of the tested extracts. Seven extracts displayed both anti-maturation and anti-biofilm activities (half maximal inhibitory concentrations IC_{50_mat} and IC_{50_biof} ≤ 100 µg/mL); Evernia prunastri and Ramalina fastigiata were the most promising lichens (IC_{50_mat} < 4 µg/mL and IC_{50_biof} < 10 µg/mL). Chemical profiles of the active extracts performed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) have been analyzed. Depsides, which were present in large amounts in the most active extracts, could be involved in anti-biofilm activities. This work confirmed that lichens represent a reservoir of compounds with anti-biofilm potential. Full article

(This article belongs to the Special Issue Lichens: Chemistry, Ecological and Biological Activities)

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Molecules, Volume 22, Issue 4 (April 2017) – 174 articles

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