The fermented manure derivative known as Preparation 500 is traditionally used as a field spray i... more The fermented manure derivative known as Preparation 500 is traditionally used as a field spray in biodynamic agriculture for maintaining and increasing soil fertility. This work aimed at characterizing the product from a microbiological standpoint and at assaying its bioactive properties. The approach involved molecular taxonomical characterization of the culturable microbial community; ARISA fingerprints of the total bacteria and fungal communities; chemical elemental macronutrient analysis via a combustion analyzer; activity assays for six key enzymes; bioassays for bacterial quorum sensing and chitolipooligosaccharide production; and plant hormone-like activity. The material was found to harbor a bacterial community of 2.38 × 10 8 CFU/g dw dominated by Gram-positives with minor instances of Actinobacteria and Gammaproteobacteria. ARISA showed a coherence of bacterial assemblages in different preparation lots of the same year in spite of geographic origin. Enzymatic activities showed elevated values of β-glucosidase, alkaline phosphatase, chitinase, and esterase. The preparation had no quorum sensing-detectable signal, and no rhizobial nod gene-inducing properties, but displayed a strong auxin-like effect on plants. Enzymatic analyses indicated a bioactive potential in the fertility and nutrient cycling contexts. The IAA activity and microbial degradation products qualify for a possible activity as soil biostimulants. Quantitative details and possible modes of action are discussed.
Manure products fermented underground in cow horns and commonly used as field spray (preparation ... more Manure products fermented underground in cow horns and commonly used as field spray (preparation 500) in the biodynamic farming system, were characterized for molecular composition by solid-state nuclear magnetic resonance [ 13 C cross-polarization magic-angle-spinning NMR (13 C-CPMAS-NMR)] spec-troscopy and offline tetramethylammonium hydroxide thermochemolysis gas chromatography-mass spectrome-try. Both thermochemolysis and NMR spectroscopy revealed a complex molecular structure, with lignin aromatic derivatives, polysaccharides, and alkyl compounds as the predominant components. CPMAS-NMR spectra of biodynamic preparations showed a carbon distribution with an overall low hydrophobic character and significant contribution of lignocellulosic derivatives. The results of thermochemolysis confirmed the characteristic highlighted by NMR spectroscopy, revealing a molecular composition based on alkyl components of plant and microbial origin and the stable incorporation of lignin derivatives. The presence of biolabile components and of undecomposed lignin compounds in the preparation 500 should be accounted to its particularly slow maturation process, as compared to common composting procedures. Our results provide, for the first time, a scientific characterization of an essential product in biodynamic agriculture, and show that biodynamic products appear to be enriched of biolabile components and, therefore, potentially conducive to plant growth stimulation.
Interactions of glyphosate (N-phosphonome-thylglycine) herbicide (GLY) with soluble fulvic acids ... more Interactions of glyphosate (N-phosphonome-thylglycine) herbicide (GLY) with soluble fulvic acids (FAs) and humic acids (HAs) at pH 5.2 and 7 were studied by 1 H and 31 P NMR spectroscopy. Increasing concentrations of soluble humic matter determined broadening and chemical shift drifts of proton and phosphorus GLY signals, thereby indicating the occurrence of weak interactions between GLY and humic superstructures. Binding was larger for FAs and pH 5.2 than for HAs and pH 7, thus suggesting formation of hydrogen bonds between GLY carboxyl and phosphonate groups and protonated oxygen functions in humic matter. Changes in relaxation and correlation times of 1 H and 31 P signals and saturation transfer difference NMR experiments confirmed the noncovalent nature of GLY−humic interactions. Diffusion-ordered NMR spectra allowed calculation of the glyphosate fraction bound to humic superstructures and association constants (K a) and Gibbs free energies of transfer for GLY−humic complex formation at both pH values. These values showed that noncovalent interactions occurred most effectively with FAs and at pH 5.2. Our findings indicated that glyphosate may spontaneously and significantly bind to soluble humic matter by noncovalent interactions at slightly acidic pH and, thus, potentially pollute natural water bodies by moving through soil profiles in complexes with dissolved humus.
The production of Mozzarella di Bufala Campana (MBC) is relevant for the agro-food economy of the... more The production of Mozzarella di Bufala Campana (MBC) is relevant for the agro-food economy of the Campania Region of Italy and the mark of Protected Designation of Origin (PDO) has been assigned to MBC in relation to its geographical origin. Advanced analytical methods must be then employed to assess authenticity, traceability, and quality of MBC. 1 H HRMAS-NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) spectroscopy was applied here to directly identify specific metabolites in MBC intact samples without time-consuming sample pre-treatments. Overcrowded conventional 1 H HRMAS-NMR spectra were selectively simplified with two NMR pulse sequences: eCPMG and eDiff, by modulating spin–spin relaxation times and diffusion of MBC molecular components, respectively. Signal elaboration of edited spectra was combined with multivariate analyses to enable significant metabolic differentiation between MBC samples from two different production sites in Campania. Principal Components Analysis (PCA) for eCPMG spectra explained 97.54% of total variance between the two MBC groups for four metabolites (b-galactose, b-lactose, acetic acid, and glycerol). Less efficient was groups distinction by PCA for eDiff spectra, although differences in polyunsaturated acids, such as linoleic and linolenic acids, were highlighted. Similarly, Discriminant Analysis (DA) provided MBC group classification with 100% success in validation tests for eCPMG spectra, while DA prediction ability was reduced to 94.12% for eDiff spectra. Hierarchical Cluster Analysis (HCA) gave a totally correct classification between the two MBC groups only for eCPMG spectra. eCPMG spectra were also used to identify metabolites during MBC aging. As compared to fresh samples, 2 days old MBC samples showed increasing signals for isobu-tylic alcohol, lactic acid, and acetic acid. This work shows that 1 H HRMAS-NMR spectroscopy can rapidly characterise the metabolic profile of intact MBC samples and statistically distinguish the geographical origin of buffalo milk mozzarella and its freshness.
After isolation from different doughs and sourdoughs, 177 strains of lactic acid bacteria were sc... more After isolation from different doughs and sourdoughs, 177 strains of lactic acid bacteria were screened at the phenotypic level for exopolysaccharide production on media containing different carbohydrate sources. Two exopolysaccharide-producing lactic acid bacteria (Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A) were selected through quantitative analysis on solid media containing sucrose and yeast extract. The PCR detection of homopolysaccharide (gtf and lev) and heteropolysaccharide (epsA, epsB, epsD and epsE, and epsEFG) genes showed different distributions within species and strains of the lactic acid bacteria studied. Moreover, in some strains both homopolysaccharide and heteropolysaccharide genes were detected. Proton nuclear magnetic resonance spectra suggest that Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A produced the same exopolysac-charide, which was constituted by a single repeating glucopyranosyl unit linked by an-(1¡6) glycosidic bond in a dextran-type carbohydrate. Microbial growth, acidification, and viscoelastic properties of sourdoughs obtained by exopolysaccharide-producing and nonproducing lactic acid bacterial strains were evaluated. Sourdough obtained after 15 h at 30°C with exopolysaccha-ride-producing lactic acid bacteria reached higher total titratable acidity as well as elastic and dissipative modulus curves with respect to the starter not producing exopolysaccharide, but they showed similar levels of pH and microbial growth. On increasing the fermentation time, no difference in the viscoelastic properties of exopolysaccharide-producing and nonproducing samples was observed. This study suggests that dextran-producing Leuconostoc lactis 95A and Lactobacillus curvatus 69B2 can be employed to prepare sourdough, and this would be particularly useful to improve the quality of baked goods while avoiding the use of commercially available hydrocolloids as texturizing additives.
A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-... more A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-yl)dihydrofuran-2-one, trivially named cerinolactone (1), has been isolated from culture filtrates of Trichoderma cerinum together with three known butenolides containing the 3,4-dialkylfuran-2(5H)-one nucleus, harzianolide (2), T39butenolide (3), and dehydroharzianolide (4). The structure of 1 was determined by spectroscopic methods, including UV, MS, and 1D and 2D NMR analyses. In vitro tests with the purified compound exhibited activity against Pythium ultimum, Rhizoctonia solani, and Botrytis cinerea.
High-resolution magic-angle-spinning (HRMAS) one-and two-dimensional 1 H and 13 C NMR spectroscop... more High-resolution magic-angle-spinning (HRMAS) one-and two-dimensional 1 H and 13 C NMR spectroscopy was used to study intact healthy (myometrium) and benign (leiomyoma) uterine tissues of 10 patients. Twenty-eight metabolites were detected and assigned in both types of tissue. Principal component analysis (PCA) was applied to a conventional water-suppressed 1 H HRMAS NMR spectrum, and two NMR spectral editing methods, namely Carr–Purcell– Meiboom–Gill (CPMG) spin-echo and diffusion-edited techniques, were used. Only the PCA of CPMG spectra resulted in a good differentiation between the two tissue types. The CPMG spin-echo spectra were also useful in indicating depleted levels of taurine in uterine leiomyomas, which were well correlated with the histopathological determination. In addition, statistical analysis revealed that most leiomyomas contained elevated concentrations of glutamate and glutamine. Our results suggest that HRMAS represents a valuable adjunct to histopathology to improve the diagnostic accuracy of uterine leiomyomas, whilst concomitantly reducing the diagnosis time.
1 H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines fro... more 1 H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines from the Campania region of Italy. The wines were obtained from three different Aglianico vineyards characterized by different microclimatic and pedological properties. In order to reach an objective evaluation of " terroir " influence on wine quality, grapes were subjected to the same winemaking procedures. The careful subtraction of water and ethanol signals from NMR spectra allowed to statistically recognize the metabolites to be employed in multivariate statistical methods: Principal Component Analysis (PCA), Dis-criminant Analysis (DA) and Hierarchical Clustering Analysis (HCA). The three wines were differentiated from each other by six metabolites:-hydroxyisobutyrate, lactic acid, succinic acid, glycerol,-fructose and-d-glucuronic acid. All multivariate analyses confirmed that the differentiation among the wines were related to micro-climate, and carbonate, clay, and organic matter content of soils. Additionally, the wine discrimination ability of NMR spectroscopy combined with chemometric methods, was proved when commercial Aglianico wines, deriving from different soils, were shown to be statistically different from the studied wines. Our findings indicate that multivariate statistical elaboration of NMR spectra of wines is a fast and accurate method to evaluate the molecular quality of wines, underlining the objective relation with terroir.
The relatively recent and advanced high-resolution magic angle spinning (HRMAS) NMR technique ena... more The relatively recent and advanced high-resolution magic angle spinning (HRMAS) NMR technique enables the direct application of NMR spectroscopy to semi-solid and gel-like samples. It combines the advantages of both solid-and liquid-state NMR by allowing to concomitantly measure intact and non-manipulated samples. Based on both 1D and 2D homo-and heteronuclear NMR spectra, HRMAS evaluates the composition of fresh semi-solid samples with a similar resolution as that of classical liquid-state NMR techniques. The enhanced spectral quality still obtained for semi-solid samples is mainly due to the MAS system, whose rapid spinning and sample orientation minimize the ani-sotropic processes that prevent the acquisition of meaningful NMR spectra for non-liquid materials. Moreover, HRMAS allows us to use edited pulse sequences which, especially in the case of biological tissues or agrofood products, may provide a simultaneous information on polar and non-polar components without the need of preliminary sample extraction. Additionally, this technique may differentiate molecular species according to their degree of mobility in hydrated matrices. The evident versatile potential of the HRMAS NMR makes this technique particularly useful for life science molecular studies. Despite the focus of HRMAS has been greatly devoted on clinical biomedicine, materials chemistry, and metabolomics, there are already enough studies that show useful applications on agricultural issues. This report reviews the latest representative studies that employ HRMAS NMR on systems related to agricultural chemistry, requiring the characterization and dynamics of soil components, plant tissues, agrofood products, and in vivo organisms.
Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants ... more Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid-and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin.
Agricultural and biorefi nery byproducts should be regarded as important sources of chemicals and... more Agricultural and biorefi nery byproducts should be regarded as important sources of chemicals and materials, instead of being disposed or burnt. Humic substances (HS) and humic-like substances (HULIS) isolated by such materials may be employed as plant biostimulants, due to their surprising bioactivity on plant development, either after their direct extraction from such byproducts or after composting them. In order to shed light on both the biological activity of HS and HULIS on plant physiology and on soil carbon dynamics, a number of analytical chemical techniques have been employed, thus, providing a detailed insight on their molecular nature. This chapter is intended to provide a comprehensive overview of the more advanced chemical techniques applied in the chemical characterization of HS and HULIS structure, such as GC-MS, NMR, HPSEC, EPR and thermal analyses. Each of these tools provides different but incomplete information on HS and HULIS molecular composition, due to both the intrinsic limitation of each technique and the large molecular heterogeneity and structural complexity of HS and HULIS. Thus, in order to elucidate the chemical nature of such sub-strates, the various analytical tools should be always exploited concomitantly and critically discussed, thus, offering a comprehensive understanding of HS and HULIS at a molecular level. Achieving this purpose will also allow to effi caciously exploit HS and HULIS as plant biostimulants in sustainable agriculture and/or biomass-based material chemistry.
In this paper, for the first time, inexpensive waterglass solutions are exploited as a new, simpl... more In this paper, for the first time, inexpensive waterglass solutions are exploited as a new, simple and ecofriendly chemical approach for promoting the formation of a silica-based coating on hemp fabrics, able to act as a thermal shield and to protect the latter from heat sources. Fourier Transform Infrared (FTIR) and solid-state Nuclear Magnetic Resonance (NMR) analysis confirm the formation of –C–O–Si– covalent bonds between the coating and the cellulosic substrate. The proposed waterglass treatment, which is resistant to washing, seems to be very effective for improving the fire behavior of hemp fabric/epoxy composites, also in combination with ammonium polyphosphate. In particular, the exploitation of hemp surface treatment and Ammonium Polyphosphate (APP) addition to epoxy favors a remarkable decrease of the Heat Release Rate (HRR), Total Heat Release (THR), Total Smoke Release (TSR) and Specific Extinction Area (SEA) (respectively by 83%, 35%, 45% and 44%) as compared to untreated hemp/epoxy composites, favoring the formation of a very stable char, as also assessed by Thermogravimetric Analysis (TGA). Because of the low interfacial adhesion between the fabrics and the epoxy matrix, the obtained composites show low strength and stiffness; however, the energy absorbed by the material is higher when using treated hemp. The presence of APP in the epoxy matrix does not affect the mechanical behavior of the composites.
Two oxidative catalytic systems, titanium dioxide (TiO 2) nanoparticles and a biomimetic Mn-porph... more Two oxidative catalytic systems, titanium dioxide (TiO 2) nanoparticles and a biomimetic Mn-porphyrin linked to montmorillonite through a spacer (MnP-M), were used to photo-polymerize soil organic matter (SOM) directly in situ on soil, with the aim to sequester organic carbon (OC) and reduce CO 2 emissions from soil. We first validated, by infra-red spectroscopy, thermogravimetric analysis (TGA), and proton spin–lattice relaxation time (T 1ρ H) in 13 C cross-polarization magic angle spinning (13 C CPMAS) nuclear magnetic resonance (NMR) spectra, the capacity of the nano-TiO 2 catalyst to photo-oxidatively couple humic molecules together by covalent bonds, as already proved under MnP-M. Both catalysts turn the loosely associated humic superstructures into more stable and larger molecular masses through a photo-oxidative free radical coupling mechanism. Then, the addition of either nano-TiO 2 or MnP-M to soil induced an in situ photo-polymerization of SOM, since exposure of catalyst-treated soils to solar light determined a significant reduction of respired CO 2 and an increase in thermal stability of humic components and, consequently, in SOC content. This suggests that both nano-TiO 2 and immobilized metal-porphyrin photo-catalysts effectively promote OC se-questration in soil and reduction of CO 2 emissions from soil to atmosphere. Soil treatments with heterogeneous photo-catalysts may become a promising technology for the development of future agricultural practices aimed to increase SOM stabilization and contribute to mitigate global climate change.
The fermented manure derivative known as Preparation 500 is traditionally used as a field spray i... more The fermented manure derivative known as Preparation 500 is traditionally used as a field spray in biodynamic agriculture for maintaining and increasing soil fertility. This work aimed at characterizing the product from a microbiological standpoint and at assaying its bioactive properties. The approach involved molecular taxonomical characterization of the culturable microbial community; ARISA fingerprints of the total bacteria and fungal communities; chemical elemental macronutrient analysis via a combustion analyzer; activity assays for six key enzymes; bioassays for bacterial quorum sensing and chitolipooligosaccharide production; and plant hormone-like activity. The material was found to harbor a bacterial community of 2.38 × 10 8 CFU/g dw dominated by Gram-positives with minor instances of Actinobacteria and Gammaproteobacteria. ARISA showed a coherence of bacterial assemblages in different preparation lots of the same year in spite of geographic origin. Enzymatic activities showed elevated values of β-glucosidase, alkaline phosphatase, chitinase, and esterase. The preparation had no quorum sensing-detectable signal, and no rhizobial nod gene-inducing properties, but displayed a strong auxin-like effect on plants. Enzymatic analyses indicated a bioactive potential in the fertility and nutrient cycling contexts. The IAA activity and microbial degradation products qualify for a possible activity as soil biostimulants. Quantitative details and possible modes of action are discussed.
Manure products fermented underground in cow horns and commonly used as field spray (preparation ... more Manure products fermented underground in cow horns and commonly used as field spray (preparation 500) in the biodynamic farming system, were characterized for molecular composition by solid-state nuclear magnetic resonance [ 13 C cross-polarization magic-angle-spinning NMR (13 C-CPMAS-NMR)] spec-troscopy and offline tetramethylammonium hydroxide thermochemolysis gas chromatography-mass spectrome-try. Both thermochemolysis and NMR spectroscopy revealed a complex molecular structure, with lignin aromatic derivatives, polysaccharides, and alkyl compounds as the predominant components. CPMAS-NMR spectra of biodynamic preparations showed a carbon distribution with an overall low hydrophobic character and significant contribution of lignocellulosic derivatives. The results of thermochemolysis confirmed the characteristic highlighted by NMR spectroscopy, revealing a molecular composition based on alkyl components of plant and microbial origin and the stable incorporation of lignin derivatives. The presence of biolabile components and of undecomposed lignin compounds in the preparation 500 should be accounted to its particularly slow maturation process, as compared to common composting procedures. Our results provide, for the first time, a scientific characterization of an essential product in biodynamic agriculture, and show that biodynamic products appear to be enriched of biolabile components and, therefore, potentially conducive to plant growth stimulation.
Interactions of glyphosate (N-phosphonome-thylglycine) herbicide (GLY) with soluble fulvic acids ... more Interactions of glyphosate (N-phosphonome-thylglycine) herbicide (GLY) with soluble fulvic acids (FAs) and humic acids (HAs) at pH 5.2 and 7 were studied by 1 H and 31 P NMR spectroscopy. Increasing concentrations of soluble humic matter determined broadening and chemical shift drifts of proton and phosphorus GLY signals, thereby indicating the occurrence of weak interactions between GLY and humic superstructures. Binding was larger for FAs and pH 5.2 than for HAs and pH 7, thus suggesting formation of hydrogen bonds between GLY carboxyl and phosphonate groups and protonated oxygen functions in humic matter. Changes in relaxation and correlation times of 1 H and 31 P signals and saturation transfer difference NMR experiments confirmed the noncovalent nature of GLY−humic interactions. Diffusion-ordered NMR spectra allowed calculation of the glyphosate fraction bound to humic superstructures and association constants (K a) and Gibbs free energies of transfer for GLY−humic complex formation at both pH values. These values showed that noncovalent interactions occurred most effectively with FAs and at pH 5.2. Our findings indicated that glyphosate may spontaneously and significantly bind to soluble humic matter by noncovalent interactions at slightly acidic pH and, thus, potentially pollute natural water bodies by moving through soil profiles in complexes with dissolved humus.
The production of Mozzarella di Bufala Campana (MBC) is relevant for the agro-food economy of the... more The production of Mozzarella di Bufala Campana (MBC) is relevant for the agro-food economy of the Campania Region of Italy and the mark of Protected Designation of Origin (PDO) has been assigned to MBC in relation to its geographical origin. Advanced analytical methods must be then employed to assess authenticity, traceability, and quality of MBC. 1 H HRMAS-NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) spectroscopy was applied here to directly identify specific metabolites in MBC intact samples without time-consuming sample pre-treatments. Overcrowded conventional 1 H HRMAS-NMR spectra were selectively simplified with two NMR pulse sequences: eCPMG and eDiff, by modulating spin–spin relaxation times and diffusion of MBC molecular components, respectively. Signal elaboration of edited spectra was combined with multivariate analyses to enable significant metabolic differentiation between MBC samples from two different production sites in Campania. Principal Components Analysis (PCA) for eCPMG spectra explained 97.54% of total variance between the two MBC groups for four metabolites (b-galactose, b-lactose, acetic acid, and glycerol). Less efficient was groups distinction by PCA for eDiff spectra, although differences in polyunsaturated acids, such as linoleic and linolenic acids, were highlighted. Similarly, Discriminant Analysis (DA) provided MBC group classification with 100% success in validation tests for eCPMG spectra, while DA prediction ability was reduced to 94.12% for eDiff spectra. Hierarchical Cluster Analysis (HCA) gave a totally correct classification between the two MBC groups only for eCPMG spectra. eCPMG spectra were also used to identify metabolites during MBC aging. As compared to fresh samples, 2 days old MBC samples showed increasing signals for isobu-tylic alcohol, lactic acid, and acetic acid. This work shows that 1 H HRMAS-NMR spectroscopy can rapidly characterise the metabolic profile of intact MBC samples and statistically distinguish the geographical origin of buffalo milk mozzarella and its freshness.
After isolation from different doughs and sourdoughs, 177 strains of lactic acid bacteria were sc... more After isolation from different doughs and sourdoughs, 177 strains of lactic acid bacteria were screened at the phenotypic level for exopolysaccharide production on media containing different carbohydrate sources. Two exopolysaccharide-producing lactic acid bacteria (Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A) were selected through quantitative analysis on solid media containing sucrose and yeast extract. The PCR detection of homopolysaccharide (gtf and lev) and heteropolysaccharide (epsA, epsB, epsD and epsE, and epsEFG) genes showed different distributions within species and strains of the lactic acid bacteria studied. Moreover, in some strains both homopolysaccharide and heteropolysaccharide genes were detected. Proton nuclear magnetic resonance spectra suggest that Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A produced the same exopolysac-charide, which was constituted by a single repeating glucopyranosyl unit linked by an-(1¡6) glycosidic bond in a dextran-type carbohydrate. Microbial growth, acidification, and viscoelastic properties of sourdoughs obtained by exopolysaccharide-producing and nonproducing lactic acid bacterial strains were evaluated. Sourdough obtained after 15 h at 30°C with exopolysaccha-ride-producing lactic acid bacteria reached higher total titratable acidity as well as elastic and dissipative modulus curves with respect to the starter not producing exopolysaccharide, but they showed similar levels of pH and microbial growth. On increasing the fermentation time, no difference in the viscoelastic properties of exopolysaccharide-producing and nonproducing samples was observed. This study suggests that dextran-producing Leuconostoc lactis 95A and Lactobacillus curvatus 69B2 can be employed to prepare sourdough, and this would be particularly useful to improve the quality of baked goods while avoiding the use of commercially available hydrocolloids as texturizing additives.
A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-... more A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-yl)dihydrofuran-2-one, trivially named cerinolactone (1), has been isolated from culture filtrates of Trichoderma cerinum together with three known butenolides containing the 3,4-dialkylfuran-2(5H)-one nucleus, harzianolide (2), T39butenolide (3), and dehydroharzianolide (4). The structure of 1 was determined by spectroscopic methods, including UV, MS, and 1D and 2D NMR analyses. In vitro tests with the purified compound exhibited activity against Pythium ultimum, Rhizoctonia solani, and Botrytis cinerea.
High-resolution magic-angle-spinning (HRMAS) one-and two-dimensional 1 H and 13 C NMR spectroscop... more High-resolution magic-angle-spinning (HRMAS) one-and two-dimensional 1 H and 13 C NMR spectroscopy was used to study intact healthy (myometrium) and benign (leiomyoma) uterine tissues of 10 patients. Twenty-eight metabolites were detected and assigned in both types of tissue. Principal component analysis (PCA) was applied to a conventional water-suppressed 1 H HRMAS NMR spectrum, and two NMR spectral editing methods, namely Carr–Purcell– Meiboom–Gill (CPMG) spin-echo and diffusion-edited techniques, were used. Only the PCA of CPMG spectra resulted in a good differentiation between the two tissue types. The CPMG spin-echo spectra were also useful in indicating depleted levels of taurine in uterine leiomyomas, which were well correlated with the histopathological determination. In addition, statistical analysis revealed that most leiomyomas contained elevated concentrations of glutamate and glutamine. Our results suggest that HRMAS represents a valuable adjunct to histopathology to improve the diagnostic accuracy of uterine leiomyomas, whilst concomitantly reducing the diagnosis time.
1 H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines fro... more 1 H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines from the Campania region of Italy. The wines were obtained from three different Aglianico vineyards characterized by different microclimatic and pedological properties. In order to reach an objective evaluation of " terroir " influence on wine quality, grapes were subjected to the same winemaking procedures. The careful subtraction of water and ethanol signals from NMR spectra allowed to statistically recognize the metabolites to be employed in multivariate statistical methods: Principal Component Analysis (PCA), Dis-criminant Analysis (DA) and Hierarchical Clustering Analysis (HCA). The three wines were differentiated from each other by six metabolites:-hydroxyisobutyrate, lactic acid, succinic acid, glycerol,-fructose and-d-glucuronic acid. All multivariate analyses confirmed that the differentiation among the wines were related to micro-climate, and carbonate, clay, and organic matter content of soils. Additionally, the wine discrimination ability of NMR spectroscopy combined with chemometric methods, was proved when commercial Aglianico wines, deriving from different soils, were shown to be statistically different from the studied wines. Our findings indicate that multivariate statistical elaboration of NMR spectra of wines is a fast and accurate method to evaluate the molecular quality of wines, underlining the objective relation with terroir.
The relatively recent and advanced high-resolution magic angle spinning (HRMAS) NMR technique ena... more The relatively recent and advanced high-resolution magic angle spinning (HRMAS) NMR technique enables the direct application of NMR spectroscopy to semi-solid and gel-like samples. It combines the advantages of both solid-and liquid-state NMR by allowing to concomitantly measure intact and non-manipulated samples. Based on both 1D and 2D homo-and heteronuclear NMR spectra, HRMAS evaluates the composition of fresh semi-solid samples with a similar resolution as that of classical liquid-state NMR techniques. The enhanced spectral quality still obtained for semi-solid samples is mainly due to the MAS system, whose rapid spinning and sample orientation minimize the ani-sotropic processes that prevent the acquisition of meaningful NMR spectra for non-liquid materials. Moreover, HRMAS allows us to use edited pulse sequences which, especially in the case of biological tissues or agrofood products, may provide a simultaneous information on polar and non-polar components without the need of preliminary sample extraction. Additionally, this technique may differentiate molecular species according to their degree of mobility in hydrated matrices. The evident versatile potential of the HRMAS NMR makes this technique particularly useful for life science molecular studies. Despite the focus of HRMAS has been greatly devoted on clinical biomedicine, materials chemistry, and metabolomics, there are already enough studies that show useful applications on agricultural issues. This report reviews the latest representative studies that employ HRMAS NMR on systems related to agricultural chemistry, requiring the characterization and dynamics of soil components, plant tissues, agrofood products, and in vivo organisms.
Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants ... more Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid-and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin.
Agricultural and biorefi nery byproducts should be regarded as important sources of chemicals and... more Agricultural and biorefi nery byproducts should be regarded as important sources of chemicals and materials, instead of being disposed or burnt. Humic substances (HS) and humic-like substances (HULIS) isolated by such materials may be employed as plant biostimulants, due to their surprising bioactivity on plant development, either after their direct extraction from such byproducts or after composting them. In order to shed light on both the biological activity of HS and HULIS on plant physiology and on soil carbon dynamics, a number of analytical chemical techniques have been employed, thus, providing a detailed insight on their molecular nature. This chapter is intended to provide a comprehensive overview of the more advanced chemical techniques applied in the chemical characterization of HS and HULIS structure, such as GC-MS, NMR, HPSEC, EPR and thermal analyses. Each of these tools provides different but incomplete information on HS and HULIS molecular composition, due to both the intrinsic limitation of each technique and the large molecular heterogeneity and structural complexity of HS and HULIS. Thus, in order to elucidate the chemical nature of such sub-strates, the various analytical tools should be always exploited concomitantly and critically discussed, thus, offering a comprehensive understanding of HS and HULIS at a molecular level. Achieving this purpose will also allow to effi caciously exploit HS and HULIS as plant biostimulants in sustainable agriculture and/or biomass-based material chemistry.
In this paper, for the first time, inexpensive waterglass solutions are exploited as a new, simpl... more In this paper, for the first time, inexpensive waterglass solutions are exploited as a new, simple and ecofriendly chemical approach for promoting the formation of a silica-based coating on hemp fabrics, able to act as a thermal shield and to protect the latter from heat sources. Fourier Transform Infrared (FTIR) and solid-state Nuclear Magnetic Resonance (NMR) analysis confirm the formation of –C–O–Si– covalent bonds between the coating and the cellulosic substrate. The proposed waterglass treatment, which is resistant to washing, seems to be very effective for improving the fire behavior of hemp fabric/epoxy composites, also in combination with ammonium polyphosphate. In particular, the exploitation of hemp surface treatment and Ammonium Polyphosphate (APP) addition to epoxy favors a remarkable decrease of the Heat Release Rate (HRR), Total Heat Release (THR), Total Smoke Release (TSR) and Specific Extinction Area (SEA) (respectively by 83%, 35%, 45% and 44%) as compared to untreated hemp/epoxy composites, favoring the formation of a very stable char, as also assessed by Thermogravimetric Analysis (TGA). Because of the low interfacial adhesion between the fabrics and the epoxy matrix, the obtained composites show low strength and stiffness; however, the energy absorbed by the material is higher when using treated hemp. The presence of APP in the epoxy matrix does not affect the mechanical behavior of the composites.
Two oxidative catalytic systems, titanium dioxide (TiO 2) nanoparticles and a biomimetic Mn-porph... more Two oxidative catalytic systems, titanium dioxide (TiO 2) nanoparticles and a biomimetic Mn-porphyrin linked to montmorillonite through a spacer (MnP-M), were used to photo-polymerize soil organic matter (SOM) directly in situ on soil, with the aim to sequester organic carbon (OC) and reduce CO 2 emissions from soil. We first validated, by infra-red spectroscopy, thermogravimetric analysis (TGA), and proton spin–lattice relaxation time (T 1ρ H) in 13 C cross-polarization magic angle spinning (13 C CPMAS) nuclear magnetic resonance (NMR) spectra, the capacity of the nano-TiO 2 catalyst to photo-oxidatively couple humic molecules together by covalent bonds, as already proved under MnP-M. Both catalysts turn the loosely associated humic superstructures into more stable and larger molecular masses through a photo-oxidative free radical coupling mechanism. Then, the addition of either nano-TiO 2 or MnP-M to soil induced an in situ photo-polymerization of SOM, since exposure of catalyst-treated soils to solar light determined a significant reduction of respired CO 2 and an increase in thermal stability of humic components and, consequently, in SOC content. This suggests that both nano-TiO 2 and immobilized metal-porphyrin photo-catalysts effectively promote OC se-questration in soil and reduction of CO 2 emissions from soil to atmosphere. Soil treatments with heterogeneous photo-catalysts may become a promising technology for the development of future agricultural practices aimed to increase SOM stabilization and contribute to mitigate global climate change.
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