The endophytic fungal community associated with leaves of Ficus carica L. (Moraceae) from Argenti... more The endophytic fungal community associated with leaves of Ficus carica L. (Moraceae) from Argentina was investigated. Fifteen fungal isolates were isolated and identified by molecular methods into the genera Alternaria, Cladosporium, Curvularia, Diaporthe, Epicoccum, Myrothecium, Neofusicoccum, Nigrospora, Preussia and Ustilago. Cladosporium cladosporioides and Curvularia lunata were the most frequently isolated species. The fungal metabolic profiles were obtained by automated TLC and NMR and analysed by PC Analysis. Antifungal and antibacterial activity was assessed by bioautographic assays. In addition, the biotransforming ability of the fungal isolates was tested on F. carica extracts. Five isolates (33.3%) exhibited inhibitory activity against at least one of the microorganisms tested. Most of the fungal endophytes were able to metabolise the flavonoid rutin 1, and the coumarin psoralen 3 present in F. carica extracts. Further investigations of the psoralen biotransforming ability performed by the selected endophyte Alternaria alternata F8 showed the accumulation of the 6,7-furan-hydrocoumaric acid derivative 4 as the main biotransformation product. Our results corroborate that F. carica can live symbiotically with rich and diverse endophytic communities adding insights about their ecological interactions.
World Journal of Microbiology and Biotechnology, 2021
Chickpea (Cicer arietinum L., Fabaceae) is the second most important legume after common bean (Ph... more Chickpea (Cicer arietinum L., Fabaceae) is the second most important legume after common bean (Phaseolus vulgaris L., Fabaceae) and third in production among the legumes grains worldwide. Ascochyta blight and Fusarium wilt are among the main fungal infections which cause the major losses of chickpea crop. In this work we report the phyto-pathogen controlling properties of 24 endophyte Phomopsis/Diaporthe isolates on the chickpea fungal pathogens Ascochyta rabiei, Fusarium oxysporum and Fusarium solani. The Phomopsis/Diaporthe strains were isolated amongst a total of 62 endophytic fungi from the aerial parts of the herbaceous perennial American plant Peperomia obtusifolia (Piperaceae) along with Fusarium, Septoria, Colletotrichum, Alternaria and Roussoella genera among others. Phomopsis/Diaporthe isolates were identified as Diaporthe infecunda (12 isolates), Diaporthe sackstoni (1 isolate), Diaporthe cf. brasiliensis (4 isolates) and Phomopsis cf. tuberivora (7 isolates). All the Phomopsis/Diaporthe strains antagonized A. rabiei strain AR2 with a mean of inhibition (% I) of 86.59 ± 1.49% in dual cultures. The metabolic characterization of the Phomopsis/Diaporthe strains showed groups in three clusters which were in agreement with the taxonomic identification. Bioautographic evaluation of organic extracts showed that those of D. cf. brasiliensis and D. infecunda were better as inhibitors. Strain Po 45 was one of the most active (cluster 1, 96.87% I), and its ethyl acetate extract inhibited A. rabiei growth in a bioautographic assay until at least 10 μg/ mm applied showing a specific chromatographic band as the responsible of the A. rabiei inhibition. Graphic abstract Electronic Supplementary Material The online version of this article (https ://doi.
The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the l... more The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the leaves of Piper crassinervium (Piperaceae) was evaluated. A literature analysis pointed out its importance as a source of prenylated bioactive molecules. The screening performed on aromatic acceptors (benzoic acids, phenols and phenylpropanoids) including geranyl diphosphate as prenyl donor, showed the biotransformation of the 3,4-dihydroxybenzoic acid by the crude extract, and the p-hydroxybenzoic acid by both the microsomal fraction and the crude extract, after treating leaves with glucose. The analysis of the products allowed the identification of C-and O-geranylated derivatives, and the protease (subtilisin and pepsin) inhibition performed on the O-geranylated compounds showed weak inhibition. Electrophoretic profiles indicated the presence of bands/spots among 56-58 kDa and pI 6-7, which are compatible with prenyltransferases. These findings show that P. crassinervium could be considered as a source of extracts with geranyltransferase activity to perform biotransformations on aromatic substrates.
Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensa... more Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2Ј-OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3-(2-chlorophenyl)-1-(2Ј-hydroxy-4Ј,6Ј-dimethoxyphenyl)prop-2-en-1-one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC ϭ 12.5 μg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC 50 ] and 90 % [MIC 90 ] of the isolates were inhibited ϭ 12.5 and 25 μg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of ϫ 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy-chalcones.
The absolute configuration of the homoisoflavanone 5,7-dihydroxy-6-methoxy-3-(9-hydroxy-phenylmet... more The absolute configuration of the homoisoflavanone 5,7-dihydroxy-6-methoxy-3-(9-hydroxy-phenylmethyl)-chroman-4-one (1), found in Polygonum species, has been determined as 3R,9R by using a combination of electronic and vibrational chiroptical spectroscopic methods. The experimental spectra were interpreted with the aid of density functional theory calculations. The risks of relying upon a single method for stereochemical characterization of natural products are discussed.
The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the l... more The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the leaves of Piper crassinervium (Piperaceae) was evaluated. A literature analysis pointed out its importance as a source of prenylated bioactive molecules. The screening performed on aromatic acceptors (benzoic acids, phenols and phenylpropanoids) including geranyl diphosphate as prenyl donor, showed the biotransformation of the 3,4-dihydroxybenzoic acid by the crude extract, and the p-hydroxybenzoic acid by both the microsomal fraction and the crude extract, after treating leaves with glucose. The analysis of the products allowed the identification of C-and O-geranylated derivatives, and the protease (subtilisin and pepsin) inhibition performed on the O-geranylated compounds showed weak inhibition. Electrophoretic profiles indicated the presence of bands/spots among 56-58 kDa and pI 6-7, which are compatible with prenyltransferases. These findings show that P. crassinervium could be considered as a source of extracts with geranyltransferase activity to perform biotransformations on aromatic substrates.
Since early in the man history, common fig was appreciated as food and for its medicinal properti... more Since early in the man history, common fig was appreciated as food and for its medicinal properties. This review explores some aspects about the importance of Ficus carica L., an amazing and ancient source of medicines and food. Topics regarding chemistry, biological activity, ethno-pharmacological uses, and its nutritional value are discussed, as well as the potential of the species as a source of new and different chemical scaffolds. Very important in the past, appreciated in our time and extremely promising in the future, F. carica represents an interesting example of healthy foods and bioproducts.
Ficus carica L. (Moraceae), also known as the common fig, is the most relevant fig species. It is... more Ficus carica L. (Moraceae), also known as the common fig, is the most relevant fig species. It is valued both as food and as medicine. Fig contains milky latex in all parenchymatous tissues, which consists of the cytoplasmic content of laticifers and is leaked in response to physical damage. In this book chapter, aspects of the chemical composition of latex from the common fig are reviewed, including proteins with enzymatic activity, fatty acids, amino acids, volatile and nonvolatile low molecular weight molecules (secondary metabolites), and rubber particles.
Homoisoflavonoids are a group of natural products mostly restricted in nature. A reduced number o... more Homoisoflavonoids are a group of natural products mostly restricted in nature. A reduced number of plant families are associated with the isolation of homoisoflavonoids: Hyacinthaceae, Liliaceae, Asparagaceae, Fabaceae, Agavaceae and Polygonaceae. Some authors have stated their chemotaxonomic value in the Hyacinthaceae family, considering homoisoflavanones as chemical markers in the sub-families Hyancinthoidea and Chlorogaloidea, Ornithogaloidea and Urginoidea. Despite they are considered as a subclass of the almost well-described flavonoids, some steps of the biosynthesis of homoisoflavonoids remain uncovered and still represent challenges to be solved. Regarding their biological activity, there are several reports describing their antioxidant, anti-diabetic, anti-inflammatory, anti-platelet, antifungal, antibacterial and antiprotozoal activity, amongst others. This book chapter revises the importance of homoisoflavonoids as non-common scaffolds of natural products, discussing their chemical aspects, chemotaxonomic value, biosynthesis and biological activities by means of a comprehensive analysis of the literature up to 2015.
The endophytic fungal community associated with leaves of Ficus carica L. (Moraceae) from Argenti... more The endophytic fungal community associated with leaves of Ficus carica L. (Moraceae) from Argentina was investigated. Fifteen fungal isolates were isolated and identified by molecular methods into the genera Alternaria, Cladosporium, Curvularia, Diaporthe, Epicoccum, Myrothecium, Neofusicoccum, Nigrospora, Preussia and Ustilago. Cladosporium cladosporioides and Curvularia lunata were the most frequently isolated species. The fungal metabolic profiles were obtained by automated TLC and NMR and analysed by PC Analysis. Antifungal and antibacterial activity was assessed by bioautographic assays. In addition, the biotransforming ability of the fungal isolates was tested on F. carica extracts. Five isolates (33.3%) exhibited inhibitory activity against at least one of the microorganisms tested. Most of the fungal endophytes were able to metabolise the flavonoid rutin 1, and the coumarin psoralen 3 present in F. carica extracts. Further investigations of the psoralen biotransforming ability performed by the selected endophyte Alternaria alternata F8 showed the accumulation of the 6,7-furan-hydrocoumaric acid derivative 4 as the main biotransformation product. Our results corroborate that F. carica can live symbiotically with rich and diverse endophytic communities adding insights about their ecological interactions.
World Journal of Microbiology and Biotechnology, 2021
Chickpea (Cicer arietinum L., Fabaceae) is the second most important legume after common bean (Ph... more Chickpea (Cicer arietinum L., Fabaceae) is the second most important legume after common bean (Phaseolus vulgaris L., Fabaceae) and third in production among the legumes grains worldwide. Ascochyta blight and Fusarium wilt are among the main fungal infections which cause the major losses of chickpea crop. In this work we report the phyto-pathogen controlling properties of 24 endophyte Phomopsis/Diaporthe isolates on the chickpea fungal pathogens Ascochyta rabiei, Fusarium oxysporum and Fusarium solani. The Phomopsis/Diaporthe strains were isolated amongst a total of 62 endophytic fungi from the aerial parts of the herbaceous perennial American plant Peperomia obtusifolia (Piperaceae) along with Fusarium, Septoria, Colletotrichum, Alternaria and Roussoella genera among others. Phomopsis/Diaporthe isolates were identified as Diaporthe infecunda (12 isolates), Diaporthe sackstoni (1 isolate), Diaporthe cf. brasiliensis (4 isolates) and Phomopsis cf. tuberivora (7 isolates). All the Phomopsis/Diaporthe strains antagonized A. rabiei strain AR2 with a mean of inhibition (% I) of 86.59 ± 1.49% in dual cultures. The metabolic characterization of the Phomopsis/Diaporthe strains showed groups in three clusters which were in agreement with the taxonomic identification. Bioautographic evaluation of organic extracts showed that those of D. cf. brasiliensis and D. infecunda were better as inhibitors. Strain Po 45 was one of the most active (cluster 1, 96.87% I), and its ethyl acetate extract inhibited A. rabiei growth in a bioautographic assay until at least 10 μg/ mm applied showing a specific chromatographic band as the responsible of the A. rabiei inhibition. Graphic abstract Electronic Supplementary Material The online version of this article (https ://doi.
The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the l... more The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the leaves of Piper crassinervium (Piperaceae) was evaluated. A literature analysis pointed out its importance as a source of prenylated bioactive molecules. The screening performed on aromatic acceptors (benzoic acids, phenols and phenylpropanoids) including geranyl diphosphate as prenyl donor, showed the biotransformation of the 3,4-dihydroxybenzoic acid by the crude extract, and the p-hydroxybenzoic acid by both the microsomal fraction and the crude extract, after treating leaves with glucose. The analysis of the products allowed the identification of C-and O-geranylated derivatives, and the protease (subtilisin and pepsin) inhibition performed on the O-geranylated compounds showed weak inhibition. Electrophoretic profiles indicated the presence of bands/spots among 56-58 kDa and pI 6-7, which are compatible with prenyltransferases. These findings show that P. crassinervium could be considered as a source of extracts with geranyltransferase activity to perform biotransformations on aromatic substrates.
Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensa... more Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2Ј-OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3-(2-chlorophenyl)-1-(2Ј-hydroxy-4Ј,6Ј-dimethoxyphenyl)prop-2-en-1-one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC ϭ 12.5 μg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC 50 ] and 90 % [MIC 90 ] of the isolates were inhibited ϭ 12.5 and 25 μg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of ϫ 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy-chalcones.
The absolute configuration of the homoisoflavanone 5,7-dihydroxy-6-methoxy-3-(9-hydroxy-phenylmet... more The absolute configuration of the homoisoflavanone 5,7-dihydroxy-6-methoxy-3-(9-hydroxy-phenylmethyl)-chroman-4-one (1), found in Polygonum species, has been determined as 3R,9R by using a combination of electronic and vibrational chiroptical spectroscopic methods. The experimental spectra were interpreted with the aid of density functional theory calculations. The risks of relying upon a single method for stereochemical characterization of natural products are discussed.
The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the l... more The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the leaves of Piper crassinervium (Piperaceae) was evaluated. A literature analysis pointed out its importance as a source of prenylated bioactive molecules. The screening performed on aromatic acceptors (benzoic acids, phenols and phenylpropanoids) including geranyl diphosphate as prenyl donor, showed the biotransformation of the 3,4-dihydroxybenzoic acid by the crude extract, and the p-hydroxybenzoic acid by both the microsomal fraction and the crude extract, after treating leaves with glucose. The analysis of the products allowed the identification of C-and O-geranylated derivatives, and the protease (subtilisin and pepsin) inhibition performed on the O-geranylated compounds showed weak inhibition. Electrophoretic profiles indicated the presence of bands/spots among 56-58 kDa and pI 6-7, which are compatible with prenyltransferases. These findings show that P. crassinervium could be considered as a source of extracts with geranyltransferase activity to perform biotransformations on aromatic substrates.
Since early in the man history, common fig was appreciated as food and for its medicinal properti... more Since early in the man history, common fig was appreciated as food and for its medicinal properties. This review explores some aspects about the importance of Ficus carica L., an amazing and ancient source of medicines and food. Topics regarding chemistry, biological activity, ethno-pharmacological uses, and its nutritional value are discussed, as well as the potential of the species as a source of new and different chemical scaffolds. Very important in the past, appreciated in our time and extremely promising in the future, F. carica represents an interesting example of healthy foods and bioproducts.
Ficus carica L. (Moraceae), also known as the common fig, is the most relevant fig species. It is... more Ficus carica L. (Moraceae), also known as the common fig, is the most relevant fig species. It is valued both as food and as medicine. Fig contains milky latex in all parenchymatous tissues, which consists of the cytoplasmic content of laticifers and is leaked in response to physical damage. In this book chapter, aspects of the chemical composition of latex from the common fig are reviewed, including proteins with enzymatic activity, fatty acids, amino acids, volatile and nonvolatile low molecular weight molecules (secondary metabolites), and rubber particles.
Homoisoflavonoids are a group of natural products mostly restricted in nature. A reduced number o... more Homoisoflavonoids are a group of natural products mostly restricted in nature. A reduced number of plant families are associated with the isolation of homoisoflavonoids: Hyacinthaceae, Liliaceae, Asparagaceae, Fabaceae, Agavaceae and Polygonaceae. Some authors have stated their chemotaxonomic value in the Hyacinthaceae family, considering homoisoflavanones as chemical markers in the sub-families Hyancinthoidea and Chlorogaloidea, Ornithogaloidea and Urginoidea. Despite they are considered as a subclass of the almost well-described flavonoids, some steps of the biosynthesis of homoisoflavonoids remain uncovered and still represent challenges to be solved. Regarding their biological activity, there are several reports describing their antioxidant, anti-diabetic, anti-inflammatory, anti-platelet, antifungal, antibacterial and antiprotozoal activity, amongst others. This book chapter revises the importance of homoisoflavonoids as non-common scaffolds of natural products, discussing their chemical aspects, chemotaxonomic value, biosynthesis and biological activities by means of a comprehensive analysis of the literature up to 2015.
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Papers by s lopez
(1), found in Polygonum species, has been determined as 3R,9R by using a combination
of electronic and vibrational chiroptical spectroscopic methods. The experimental spectra were
interpreted with the aid of density functional theory calculations. The risks of relying upon a single
method for stereochemical characterization of natural products are discussed.
Books by s lopez
(1), found in Polygonum species, has been determined as 3R,9R by using a combination
of electronic and vibrational chiroptical spectroscopic methods. The experimental spectra were
interpreted with the aid of density functional theory calculations. The risks of relying upon a single
method for stereochemical characterization of natural products are discussed.