The asymmetric aldol and Michael reactions, as the most prominent carbon-carbon bond formation re... more The asymmetric aldol and Michael reactions, as the most prominent carbon-carbon bond formation reactions, are the central study issues in the field of asymmetric synthesis. In this study, promiscuous aldo-ketoreductase (AKR) used to catalyze aldol reaction. between aromatic aldehydes and ketones. Good yield (up to 75%),moderate enantioselectivity (60%), and high diastereoselectivity (dr) up to 93/7 (anti/syn) were obtained. Several mimetic peptides from AKR’s active site were designed and synthesized as asymmetric catalysts in the aldol and Michael reactions. Mimetic peptides PE16aa (1), PH16aa (2), 16aa (3), 8aa (4), 8aa-z (5), 5aa (6), 3aa (7), Fmoc-KLH-R (8), K(z)LH-R (9), PYE (10), PEY (11), PHE (12), PEH (13),LFV (14) 4a and 4b were successfully synthesized using manually solid phase peptide synthesis protocol. Then, all of these mimetic peptides were employed to catalyze aldol reactions and peptides 2, 4, 4a, 4b, 10, 11, 12, and 13 were selected to catalyze Michael reactions. ...
In modern pharmacology, about half of the useful drugs are derived from natural sources where dru... more In modern pharmacology, about half of the useful drugs are derived from natural sources where drug discovery from nature is an attractive subject for researchers. Monascus spp. has the ability in producing a collection of useful secondary metabolite which can be applied in food, cosmetic and pharmaceutics. In this study, the potential of Monascus purpureus FTC5391 in producing metabolites in solid state and submerged cultivation was investigated. The ethanolic extraction of these fermented products was evaluated using HPLC-PDA and GCMS. The results showed that the profiling of metabolites produced by Monascus purpureus FTC5391 in two different types of cultivation employed different media was significantly varied. The number of metabolites detected in Hiroi-pd submerged and soybean solid state cultivation was 100 and 55 compounds respectively with 10% similarity. These results demonstrated that the types of substrate were greatly affected on the number and sort of metabolites produc...
pH-responsive virus-like nanoparticles (VLNPs) hold promising potential as drug delivery systems ... more pH-responsive virus-like nanoparticles (VLNPs) hold promising potential as drug delivery systems for cancer therapy. In the present study, hepatitis B virus (HBV) VLNPs harbouring His-tags were used to display doxorubicin (DOX) via nitrilotriacetic acid (NTA) conjugation. The His-tags served as pH-responsive nanojoints which released DOX from VLNPs in a controlled manner. The His-tagged VLNPs conjugated non-covalently with NTA-DOX, and cross-linked with folic acid (FA) were able to specifically target and deliver the DOX into ovarian cancer cells via folate receptor (FR)-mediated endocytosis. The cytotoxicity and cellular uptake results revealed that the His-tagged VLNPs significantly increased the accumulation of DOX in the ovarian cancer cells and enhanced the uptake of DOX, which improved anti-tumour effects. This study demonstrated that NTA-DOX can be easily displayed on His-tagged VLNPs by a simple Add-and-Display step with high coupling efficiency and the drug was only release...
In this study, a simple, green and eco-friendly method was used for the synthesis of silver nanop... more In this study, a simple, green and eco-friendly method was used for the synthesis of silver nanoparticles (Ag-NPs) in alkaline treated Tapioca starch. The XRD results indicated that Ag-NPs were produced after stirring for several hours at 80°C. TEM image showed the Ag-NPs were in spherical shape with average size of 11 nm. The UV-vis results revealed clearly the formation of Ag-NPs in the range from 410 to 420 nm. Moreover, the prepared nanoparticles showed good catalytic activity in the reduction of 4-nitrophenol (4-NP). The results confirmed the catalytic activity of them in the short induction period, and the completion reaction continued within 15 min. The finding revealed also significant shift in the DPPH radical scavenging ability for studied samples. The recorded scavenging ability for the lowest concentration of the synthesized Ag-NP (50 lg/ ml) was 17.29 ± 0.06 and this scavenging ability was increased to 78.60 ± 0.05, when concentration
Journal of Photochemistry and Photobiology B: Biology, 2016
The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco... more The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco-friendly approach. The present work was undertaken to develop zinc oxide nanoparticles (ZnO-NPs) by a green method using simple precursor from the solution consisting of zinc acetate and the flower extract of Anchusa italica (A. italica). Effect of annealing temperature on structural and antimicrobial properties was investigated. The crystalline structure of ZnO-NPs was shown using X-ray diffraction (XRD) analysis. Transmission electron microscopy (TEM) results showed that ZnO-NPs are hexagonal in shapes with mean particle size of ~8 and ~14nm at 100°C and 200°C annealing temperatures respectively. The optical band gap was increased from 3.27eV to 3.30eV with the decreasing of the particle size. The antimicrobial activity of ZnO-NPs towards Gram positive (Bacillus megaterium and Stapphylococcus aureus) and Gram negative (Escherichia coli and Salmonella typhimurium) pathogens decreased with the increasing of the heat treating temperature. In vitro cytotoxicity studies on Vero cells, a dose dependent toxicity with nontoxic effect of concentration below 142μg/mL was shown. The results indicated that A. italica is an appropriate reaction media to prepare ZnO-NPs for cosmetic and bio-medical productions.
To investigate the influence of pH on the size and distribution of silver nanoparticles (Ag-NPs) ... more To investigate the influence of pH on the size and distribution of silver nanoparticles (Ag-NPs) as well as the antibacterial activity and catalytic performance of rice straw/silver nanocomposites (RS/Ag-NCs), Ag-NPs were synthesized on the surface of rice straw (RS) with various percentages of Ag-NPs (1.0, 5.0, 10.0, and 20.0 wt.%) under different temperatures and diverse pH values. The ultraviolet-visible spectroscopy of synthesized RS/Ag-NCs became noticeable with increased pH, and the peaks were blue-shifted to lower wavelengths. X-ray powder diffraction (PXRD) demonstrated the presence of pure Ag-NPs. Transmission electron microscopy (TEM) showed that the diameters of Ag-NPs on RS were between 7.78 and 2.84 nm at pH values of 8 to 10. The antibacterial activity of various sizes of Ag-NPs on RS was examined using Gramnegative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) based on the well diffusion technique. Higher antibacterial activity was detected as the loading percentage of RS/Ag-NCs increased and particle size decreased. The superior catalytic performance of 20.0 wt.% RS/Ag-NCs was considered in a test reaction in 4-nitrophenol (4-NP) reduction in the presence of sodium borohydride (NaBH4) in an eco-friendly solvent at ambient temperature. The results represented the high-performance catalytic activity of 20.0 wt.% RS/Ag-NCs.
Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical the... more Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently,Monascusfermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity ofMonascus purpureusFTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythrito...
A series of tripeptide organocatalysts containing a secondary amine group and two amino acids wit... more A series of tripeptide organocatalysts containing a secondary amine group and two amino acids with polar side chain units were developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The effectiveness of short polar peptides as asymmetric catalysts in aldol reactions to attain high yields of enantio-and diastereoselective isomers were investigated. In a comparison, glutamic acid and histidine produced higher % ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric aldol addition reaction in aqueous media. Chirality 25:726-734, 2013.
Excellent yield (up to 97%), enantioselectivity (up to 99%) and diastereoselectivity (up to 99/1)... more Excellent yield (up to 97%), enantioselectivity (up to 99%) and diastereoselectivity (up to 99/1) were obtained using mimetic peptides.
Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical the... more Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently, Monascus fermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity of Monascus purpureus FTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythritol, which act as coronary vasodilator compounds.
ABSTRACT The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for... more ABSTRACT The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for the first time to catalyze asymmetric aldol reactions in aqueous medium. The reactions between aromatic aldehydes and cyclic/acyclic ketones give the corresponding products in moderate yields and enantioselectivities in the presence of water. The influence of solvents, the mole ratio of substrates, and enzyme concentration are investigated. The mechanism of the AKR1A1-catalyzed aldol reaction is also discussed.
ABSTRACT This work reports the effectiveness of short polar peptides as asymmetric catalysts in M... more ABSTRACT This work reports the effectiveness of short polar peptides as asymmetric catalysts in Michael reactions to attain good yields of enantio- and diastereoselective isomers. In a comparison, glutamic acid and histidine produced greater ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric Michael addition reaction in water. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
Bioactive compounds of the body wall of the sea cucumber (Holothuria leucospilota) collected from... more Bioactive compounds of the body wall of the sea cucumber (Holothuria leucospilota) collected from the Persian Gulf were extracted using methanol and analyze separation was determined by GCMS. Extracts were evaluated for their antibacterial and antifungal activities against Gram positive and Gram negative bacteria and also Candida species by using disk diffusion and broth microdilution susceptibility tests. Efficacy of extract was evaluated against sessile yeast and bacterial cells by the timedependent killing assay. GCMS analysis clearly showed the presence of twenty important constituents. The major determined bioactive compound in methanolic extract was fatty acids. The preliminary test showed significant antimicrobial activity for all isolates tested (with zone of inhibition ranging from 7.1 ? 0.56 to 14.1 ? 0.91 mm). The inhibition zones for Candida species tested were ranged from 7.4 ? 0.75 to 14.7 ? 0.46 mm. The MICs value were ranged from 5 ? 0.02 to 80 ? 0.75 mg/ml for bacteria tested, while Candida species were more susceptible to extract and MICs were ranged from 0.75 ? 0.01 to 25 ? 0.90 mg/ml. All isolates tested were showed significant reduction of cells started from 26 h incubation. It is also indicated that Candida albicans was more susceptible in terms of decreasing the number of cells after 24 h incubation time in compare to other species.
The asymmetric aldol and Michael reactions, as the most prominent carbon-carbon bond formation re... more The asymmetric aldol and Michael reactions, as the most prominent carbon-carbon bond formation reactions, are the central study issues in the field of asymmetric synthesis. In this study, promiscuous aldo-ketoreductase (AKR) used to catalyze aldol reaction. between aromatic aldehydes and ketones. Good yield (up to 75%),moderate enantioselectivity (60%), and high diastereoselectivity (dr) up to 93/7 (anti/syn) were obtained. Several mimetic peptides from AKR’s active site were designed and synthesized as asymmetric catalysts in the aldol and Michael reactions. Mimetic peptides PE16aa (1), PH16aa (2), 16aa (3), 8aa (4), 8aa-z (5), 5aa (6), 3aa (7), Fmoc-KLH-R (8), K(z)LH-R (9), PYE (10), PEY (11), PHE (12), PEH (13),LFV (14) 4a and 4b were successfully synthesized using manually solid phase peptide synthesis protocol. Then, all of these mimetic peptides were employed to catalyze aldol reactions and peptides 2, 4, 4a, 4b, 10, 11, 12, and 13 were selected to catalyze Michael reactions. ...
In modern pharmacology, about half of the useful drugs are derived from natural sources where dru... more In modern pharmacology, about half of the useful drugs are derived from natural sources where drug discovery from nature is an attractive subject for researchers. Monascus spp. has the ability in producing a collection of useful secondary metabolite which can be applied in food, cosmetic and pharmaceutics. In this study, the potential of Monascus purpureus FTC5391 in producing metabolites in solid state and submerged cultivation was investigated. The ethanolic extraction of these fermented products was evaluated using HPLC-PDA and GCMS. The results showed that the profiling of metabolites produced by Monascus purpureus FTC5391 in two different types of cultivation employed different media was significantly varied. The number of metabolites detected in Hiroi-pd submerged and soybean solid state cultivation was 100 and 55 compounds respectively with 10% similarity. These results demonstrated that the types of substrate were greatly affected on the number and sort of metabolites produc...
pH-responsive virus-like nanoparticles (VLNPs) hold promising potential as drug delivery systems ... more pH-responsive virus-like nanoparticles (VLNPs) hold promising potential as drug delivery systems for cancer therapy. In the present study, hepatitis B virus (HBV) VLNPs harbouring His-tags were used to display doxorubicin (DOX) via nitrilotriacetic acid (NTA) conjugation. The His-tags served as pH-responsive nanojoints which released DOX from VLNPs in a controlled manner. The His-tagged VLNPs conjugated non-covalently with NTA-DOX, and cross-linked with folic acid (FA) were able to specifically target and deliver the DOX into ovarian cancer cells via folate receptor (FR)-mediated endocytosis. The cytotoxicity and cellular uptake results revealed that the His-tagged VLNPs significantly increased the accumulation of DOX in the ovarian cancer cells and enhanced the uptake of DOX, which improved anti-tumour effects. This study demonstrated that NTA-DOX can be easily displayed on His-tagged VLNPs by a simple Add-and-Display step with high coupling efficiency and the drug was only release...
In this study, a simple, green and eco-friendly method was used for the synthesis of silver nanop... more In this study, a simple, green and eco-friendly method was used for the synthesis of silver nanoparticles (Ag-NPs) in alkaline treated Tapioca starch. The XRD results indicated that Ag-NPs were produced after stirring for several hours at 80°C. TEM image showed the Ag-NPs were in spherical shape with average size of 11 nm. The UV-vis results revealed clearly the formation of Ag-NPs in the range from 410 to 420 nm. Moreover, the prepared nanoparticles showed good catalytic activity in the reduction of 4-nitrophenol (4-NP). The results confirmed the catalytic activity of them in the short induction period, and the completion reaction continued within 15 min. The finding revealed also significant shift in the DPPH radical scavenging ability for studied samples. The recorded scavenging ability for the lowest concentration of the synthesized Ag-NP (50 lg/ ml) was 17.29 ± 0.06 and this scavenging ability was increased to 78.60 ± 0.05, when concentration
Journal of Photochemistry and Photobiology B: Biology, 2016
The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco... more The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco-friendly approach. The present work was undertaken to develop zinc oxide nanoparticles (ZnO-NPs) by a green method using simple precursor from the solution consisting of zinc acetate and the flower extract of Anchusa italica (A. italica). Effect of annealing temperature on structural and antimicrobial properties was investigated. The crystalline structure of ZnO-NPs was shown using X-ray diffraction (XRD) analysis. Transmission electron microscopy (TEM) results showed that ZnO-NPs are hexagonal in shapes with mean particle size of ~8 and ~14nm at 100°C and 200°C annealing temperatures respectively. The optical band gap was increased from 3.27eV to 3.30eV with the decreasing of the particle size. The antimicrobial activity of ZnO-NPs towards Gram positive (Bacillus megaterium and Stapphylococcus aureus) and Gram negative (Escherichia coli and Salmonella typhimurium) pathogens decreased with the increasing of the heat treating temperature. In vitro cytotoxicity studies on Vero cells, a dose dependent toxicity with nontoxic effect of concentration below 142μg/mL was shown. The results indicated that A. italica is an appropriate reaction media to prepare ZnO-NPs for cosmetic and bio-medical productions.
To investigate the influence of pH on the size and distribution of silver nanoparticles (Ag-NPs) ... more To investigate the influence of pH on the size and distribution of silver nanoparticles (Ag-NPs) as well as the antibacterial activity and catalytic performance of rice straw/silver nanocomposites (RS/Ag-NCs), Ag-NPs were synthesized on the surface of rice straw (RS) with various percentages of Ag-NPs (1.0, 5.0, 10.0, and 20.0 wt.%) under different temperatures and diverse pH values. The ultraviolet-visible spectroscopy of synthesized RS/Ag-NCs became noticeable with increased pH, and the peaks were blue-shifted to lower wavelengths. X-ray powder diffraction (PXRD) demonstrated the presence of pure Ag-NPs. Transmission electron microscopy (TEM) showed that the diameters of Ag-NPs on RS were between 7.78 and 2.84 nm at pH values of 8 to 10. The antibacterial activity of various sizes of Ag-NPs on RS was examined using Gramnegative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) based on the well diffusion technique. Higher antibacterial activity was detected as the loading percentage of RS/Ag-NCs increased and particle size decreased. The superior catalytic performance of 20.0 wt.% RS/Ag-NCs was considered in a test reaction in 4-nitrophenol (4-NP) reduction in the presence of sodium borohydride (NaBH4) in an eco-friendly solvent at ambient temperature. The results represented the high-performance catalytic activity of 20.0 wt.% RS/Ag-NCs.
Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical the... more Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently,Monascusfermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity ofMonascus purpureusFTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythrito...
A series of tripeptide organocatalysts containing a secondary amine group and two amino acids wit... more A series of tripeptide organocatalysts containing a secondary amine group and two amino acids with polar side chain units were developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The effectiveness of short polar peptides as asymmetric catalysts in aldol reactions to attain high yields of enantio-and diastereoselective isomers were investigated. In a comparison, glutamic acid and histidine produced higher % ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric aldol addition reaction in aqueous media. Chirality 25:726-734, 2013.
Excellent yield (up to 97%), enantioselectivity (up to 99%) and diastereoselectivity (up to 99/1)... more Excellent yield (up to 97%), enantioselectivity (up to 99%) and diastereoselectivity (up to 99/1) were obtained using mimetic peptides.
Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical the... more Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently, Monascus fermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity of Monascus purpureus FTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythritol, which act as coronary vasodilator compounds.
ABSTRACT The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for... more ABSTRACT The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for the first time to catalyze asymmetric aldol reactions in aqueous medium. The reactions between aromatic aldehydes and cyclic/acyclic ketones give the corresponding products in moderate yields and enantioselectivities in the presence of water. The influence of solvents, the mole ratio of substrates, and enzyme concentration are investigated. The mechanism of the AKR1A1-catalyzed aldol reaction is also discussed.
ABSTRACT This work reports the effectiveness of short polar peptides as asymmetric catalysts in M... more ABSTRACT This work reports the effectiveness of short polar peptides as asymmetric catalysts in Michael reactions to attain good yields of enantio- and diastereoselective isomers. In a comparison, glutamic acid and histidine produced greater ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric Michael addition reaction in water. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
Bioactive compounds of the body wall of the sea cucumber (Holothuria leucospilota) collected from... more Bioactive compounds of the body wall of the sea cucumber (Holothuria leucospilota) collected from the Persian Gulf were extracted using methanol and analyze separation was determined by GCMS. Extracts were evaluated for their antibacterial and antifungal activities against Gram positive and Gram negative bacteria and also Candida species by using disk diffusion and broth microdilution susceptibility tests. Efficacy of extract was evaluated against sessile yeast and bacterial cells by the timedependent killing assay. GCMS analysis clearly showed the presence of twenty important constituents. The major determined bioactive compound in methanolic extract was fatty acids. The preliminary test showed significant antimicrobial activity for all isolates tested (with zone of inhibition ranging from 7.1 ? 0.56 to 14.1 ? 0.91 mm). The inhibition zones for Candida species tested were ranged from 7.4 ? 0.75 to 14.7 ? 0.46 mm. The MICs value were ranged from 5 ? 0.02 to 80 ? 0.75 mg/ml for bacteria tested, while Candida species were more susceptible to extract and MICs were ranged from 0.75 ? 0.01 to 25 ? 0.90 mg/ml. All isolates tested were showed significant reduction of cells started from 26 h incubation. It is also indicated that Candida albicans was more susceptible in terms of decreasing the number of cells after 24 h incubation time in compare to other species.
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