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Harry Gruppen - One of the best experts on this subject based on the ideXlab platform.
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Structural Changes of 6a-Hydroxy-Pterocarpans Upon Heating Modulate Their Estrogenicity
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Milou G.m. Van De Schans, Alfredo David Cervantes, Madelon J. Logtenberg, Toine Frank Henk Bovee, Jean-paul Vincken, Harry GruppenAbstract:The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-Pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-Pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ). In particular, the response toward ERα changed, from agonistic for glyceollins to antagonistic for dehydroglyceollins. Toward ERβ a decrease in agonistic activity was observed. These results indicate that the introduction of a double bond with the concomitant loss of a hydroxyl group in 6a-hydroxy-pte...
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Structural Changes of 6a-Hydroxy-Pterocarpans Upon Heating Modulate Their Estrogenicity
2014Co-Authors: Milou G. M. Van De Schans, Alfredo David Cervantes, Madelon J. Logtenberg, Jean-paul Vincken, Toine F H Bovee, Harry GruppenAbstract:The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-Pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-Pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ). In particular, the response toward ERα changed, from agonistic for glyceollins to antagonistic for dehydroglyceollins. Toward ERβ a decrease in agonistic activity was observed. These results indicate that the introduction of a double bond with the concomitant loss of a hydroxyl group in 6a-hydroxy-Pterocarpans extensively modulates their estrogenic activity
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Modulation of isoflavonoid composition of Rhizopus oryzae elicited soybean (Glycine max) seedlings by light and wounding.
Journal of agricultural and food chemistry, 2013Co-Authors: Siti Aisyah, Harry Gruppen, Betty Madzora, Jean-paul VinckenAbstract:The isoflavonoid profile of soybean was altered in different ways by stimulation of defense response upon germination. The combination of simultaneous germination and induction by Rhizopus oryzae increased the total isoflavonoid content of soybeans over 2-fold. Pterocarpans became the predominant isoflavonoids, up to 50% (w/w) of total isoflavonoids. To modulate both isoflavonoid content and composition further, the treatment was extended with wounding or light stimuli. The total isoflavonoid content could be increased over 3-fold compared to untreated beans by growing fungus-elicited soybean seedlings in light, whereas wounding was less effective. Interestingly, light altered the composition of prenylated Pterocarpans by mediating the position of prenylation. The 2-prenylated pterocarpan level increased 2-fold, whereas that of 4-prenylated pterocarpan remained similar. Taken together, fungus was the most effective elicitor to alter the isoflavonoid content and composition of soybean seedlings, the impact of which can be further enhanced and mediated by additional stimuli, particularly light.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
Jean-paul Vincken - One of the best experts on this subject based on the ideXlab platform.
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Structural Changes of 6a-Hydroxy-Pterocarpans Upon Heating Modulate Their Estrogenicity
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Milou G.m. Van De Schans, Alfredo David Cervantes, Madelon J. Logtenberg, Toine Frank Henk Bovee, Jean-paul Vincken, Harry GruppenAbstract:The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-Pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-Pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ). In particular, the response toward ERα changed, from agonistic for glyceollins to antagonistic for dehydroglyceollins. Toward ERβ a decrease in agonistic activity was observed. These results indicate that the introduction of a double bond with the concomitant loss of a hydroxyl group in 6a-hydroxy-pte...
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Structural Changes of 6a-Hydroxy-Pterocarpans Upon Heating Modulate Their Estrogenicity
2014Co-Authors: Milou G. M. Van De Schans, Alfredo David Cervantes, Madelon J. Logtenberg, Jean-paul Vincken, Toine F H Bovee, Harry GruppenAbstract:The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-Pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-Pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ). In particular, the response toward ERα changed, from agonistic for glyceollins to antagonistic for dehydroglyceollins. Toward ERβ a decrease in agonistic activity was observed. These results indicate that the introduction of a double bond with the concomitant loss of a hydroxyl group in 6a-hydroxy-Pterocarpans extensively modulates their estrogenic activity
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Modulation of isoflavonoid composition of Rhizopus oryzae elicited soybean (Glycine max) seedlings by light and wounding.
Journal of agricultural and food chemistry, 2013Co-Authors: Siti Aisyah, Harry Gruppen, Betty Madzora, Jean-paul VinckenAbstract:The isoflavonoid profile of soybean was altered in different ways by stimulation of defense response upon germination. The combination of simultaneous germination and induction by Rhizopus oryzae increased the total isoflavonoid content of soybeans over 2-fold. Pterocarpans became the predominant isoflavonoids, up to 50% (w/w) of total isoflavonoids. To modulate both isoflavonoid content and composition further, the treatment was extended with wounding or light stimuli. The total isoflavonoid content could be increased over 3-fold compared to untreated beans by growing fungus-elicited soybean seedlings in light, whereas wounding was less effective. Interestingly, light altered the composition of prenylated Pterocarpans by mediating the position of prenylation. The 2-prenylated pterocarpan level increased 2-fold, whereas that of 4-prenylated pterocarpan remained similar. Taken together, fungus was the most effective elicitor to alter the isoflavonoid content and composition of soybean seedlings, the impact of which can be further enhanced and mediated by additional stimuli, particularly light.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
Ki Hun Park - One of the best experts on this subject based on the ideXlab platform.
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Potent Inhibition of Bacterial Neuraminidase Activity by Pterocarpans Isolated from the Roots of Lespedeza bicolor.
ChemInform, 2012Co-Authors: Marcus J. Curtis-long, Jae Eun Kang, Ki Hun ParkAbstract:Six Pterocarpans, including the three new Pterocarpans bicolosin A—C (I), displaying significant levels of neuraminidase inhibitory activity are isolated and characterized.
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pterocarpan profiles for soybean leaves at different growth stages and investigation of their glycosidase inhibitions
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Marcus J Curtislong, Ki Chang Jang, Kyu-young Kang, Ki Hun ParkAbstract:Soybean leaves are eaten as seasonal edible greens in Korea. Analysis of the ethyl acetate extract of these leaves showed that it exhibited potent and selective neuraminidase inhibition, which began at the R3 stage and peaked at R7. Ten Pterocarpans, including the new 6a-hydroxypterocarpan 10, were isolated from soybean leaves and their inhibition activities tested against a range of glycosidases. The relationship between structure and enzyme inhibition was investigated: 6a-hydroxyPterocarpans exhibited much higher inhibition against neuraminidase (IC50 = 2.4–89.4 μM) than α-glucosidase (IC50 = 90.4– >100 μM). Glyceollin VII (7) displayed 40-fold greater activity (IC50 = 2.4 μM) against neuraminidase than α-glucosidase (IC50 = 90.4 μM). On the other hand, coumestanes (1–3) were good α-glucosidase inhibitors (IC50 = 6.0–42.6 μM). In kinetic analysis, the most potent neuraminidase inhibitors (5–10) were noncompetitive. HPLC analysis indicated that most pterocarpan synthesis began from the R3 stage, and a ra...
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Potent inhibition of bacterial neuraminidase activity by Pterocarpans isolated from the roots of Lespedeza bicolor
Bioorganic & Medicinal Chemistry Letters, 2011Co-Authors: Marcus J. Curtis-long, Jae Eun Kang, Ki Hun ParkAbstract:Abstract Bacterial neuraminidase has been highlighted as a key enzyme for pathogenic infection and sepsis. Six Pterocarpans displaying significant levels of neuraminidase inhibitory activity were isolated from the root bark of Lespedeza bicolor . The isolated compounds were identified as three new Pterocarpans ( 1 − 3 ) together with known compounds erythrabyssin II ( 4 ), lespebuergine G4 ( 5 ), and 1-methoxyerythrabyssin II ( 6 ). The new compounds were characterized as bicolosin A ( 1 ), bicolosin B ( 2 ), and bicolosin C ( 3 ). All compounds inhibited bacterial neuraminidase in a dose-dependent manner with significant inhibition (IC 50 = 0.09–3.25 μM). All neuraminidase inhibitors screened were found to exhibit noncompetitive kinetics. The three most potent neuraminidase inhibitors ( 1, 3 and 6 ) feature a methoxy substitution on C-1.
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Pterocarpans and flavanones from Sophora flavescens displaying potent neuraminidase inhibition
Bioorganic & Medicinal Chemistry Letters, 2008Co-Authors: Marcus J. Curtis-long, Min Suk Yang, Seong-hun Jeong, Ki Hun ParkAbstract:Pterocarpans (1-3) and flavanones (4-10) were isolated from Sophora flavescens and screened for their ability to inhibit neuraminidase (an enzyme crucial in the proliferation of the influenza virus). The major- ity of inhibitors were shown to have IC50 values of 20 lM or below. Interestingly, pterocarpan 1 emerged as the best inhibitor with an IC50 of 1.4 lM. We were thus able to prove that the pterocarpan skeleton is a new class of lead structure for neuraminidase inhibitors. Our studies reveal that the IC50 has a marked dependence upon structure in the case of the Pterocarpans but much less so for the flavanones. Kinetic analysis disclosed that all inhibitors are noncompetitive. Our molecular docking experiment resulted that the most potent pterocarpan-derived inhibitor 1 may bind to another binding pocket adjacent to the active site.
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LDL-Antioxidant Pterocarpans from Roots of Glycine max (L.) Merr.
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Taesook Jeong, Ki Hun ParkAbstract:The methanolic root extract of Glycine max (L.) Merr. was chromatographed, which yielded 10 flavonoids, including three isoflavones 1−3, five Pterocarpans 4−8, one flavonol 9, and one anthocyanidin 10. All isolated compounds were examined for LDL-antioxidant activities using four different assay systems on the basis of Cu2+-mediated oxidation. Among them, seven compounds showed potent LDL-antioxidant activities in the thiobarbituric acid reactive substances (TBARS) assay, the lag time of conjugated diene formation, relative electrophoretic mobility (REM), and fragmentation of apoB-100 on copper-mediated LDL oxidation. Three Pterocarpans 4, 6, and 7, never reported as LDL-antioxidant, showed potent activities with IC50 values of 19.8, 0.9, 45.0 μM, respectively, in comparison with probucol (IC50 = 5.6 μM) as positive control. Interestingly, coumestrol 6 (IC50 = 0.9 μM) showed 20 times more activity in the TBARS assay than genistein (IC50 = 30.1 μM) and daidzein (IC50 = 21.6 μM), representative antioxidants...
Wolfgang Barz - One of the best experts on this subject based on the ideXlab platform.
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Constitutive and elicitation induced metabolism of isoflavones and Pterocarpans in chickpea (Cicer arietinum) cell suspension cultures
Plant Cell Tissue and Organ Culture, 1994Co-Authors: Wolfgang Barz, Ulrike MackenbrockAbstract:Constitutive phenolics of chickpea cell suspension cultures are the isoflavones formononetin and biochanin A, the isoflavanones homoferreirin and cicerin and the Pterocarpans medicarpin and maackiain. They accumulate as vacuolar malonylglucosides. The biosynthetic pathways to isoflavones, Pterocarpans and malonylglucoside conjugates together with their enzymes are explained. Elicitation of cell cultures leads to pronounced increases in the activities of biosynthetic enzymes with differential effects on the enzymes involved in conjugate metabolism. Low elicitor doses favour pterocarpan conjugate formation whereas high doses lead to pterocarpan aglycone accumulation accompanied by vacuolar efflux of formononetin and pterocarpan malonylglucosides. Elicitor-induced changes in enzyme activities and vacuolar efflux of conjugates are prevented by application of 10-3M concentrations of cinnamic acid. Cinnamate is alternatively metabolized to a glucose ester, a S-glutathionyl conjugate and to cell wall bounds forms; these reactions are intensified by elicitation. Isoflavone and pterocarpan biosynthesis and conjugate metabolism as regulated by elicitation and cinnamate is depicted in a metabolic grid to explain the complex regulatory pattern of phenolic accumulation in chickpea cell cultures.
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Purification and characterization of pterocarpan hydroxylase, a flavoprotein monooxygenase from the fungus Ascochyta rabiei involved in pterocarpan phytoalexin metabolism
Archives of Microbiology, 1991Co-Authors: Raimund Tenhaken, H. Ch. Salmen, Wolfgang BarzAbstract:Crude protein extracts from the chickpea ( Cicer arietinum ) pathogenic fungus Ascochyta rabiei catalyze the hydroxylation of the pterocarpan phytoalexins medicarpin and maackiain to the corresponding 1 a -hydroxy-1,4-diene-3-one derivatives. The enzyme reaction depends on NAD(P)H and molecular oxygen. Low amounts of FAD are necessary for maximal enzyme activity. The pterocarpan hydroxylase is a new flavoprotein monooxygenase with a molecular weight of 58 kDa in SDS-PAGE. The soluble enzyme can utilize NADH and NADPH with similar values for K _m and V _max respectively. The pterocarpan hydroxylase and a pterocarpan reductase ( M _r 29 kDa; Höhl and Barz 1987) are constitutively expressed by A. rabiei isolates.
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elicitor induced formation of pterocarpan phytoalexins in chickpea cicer arietinum l cell suspension cultures from constitutive isoflavone conjugates upon inhibition of phenylalanine ammonia lyase
Zeitschrift für Naturforschung C, 1991Co-Authors: Ulrike Mackenbrock, Wolfgang BarzAbstract:Regulatory pattern of constitutive isoflowone conjugate turnover and elicitor-caused pterocarpan biosynthesis in chikpea cell suspension cultures. Using a specific PAL inhibitor in combination with feeding experiments we tried to demonstrate whether the formation of Pterocarpans will always proceed de novo or whether the demand for isoflavane intermediate may not be covered from the constitutive pool of the formononetin malonylglucoside
Rudy Simons - One of the best experts on this subject based on the ideXlab platform.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
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increasing soy isoflavonoid content and diversity by simultaneous malting and challenging by a fungus to modulate estrogenicity
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Rudy Simons, Marian A. Verbruggen, Jean-paul Vincken, Nikolaos Roidos, Toine F H Bovee, Martijn Van Iersel, Harry GruppenAbstract:Soybeans were germinated on a kilogram-scale, by the application of malting technology used in the brewing industry, and concomitantly challenged with Rhizopus microsporus var. oryzae. In a time-course experiment, samples were taken every 24 h for 10 days, and the isoflavonoid profile was analyzed by RP-UHPLC-MS. Upon induction with R. microsporus, the isoflavonoid composition changed drastically with the formation of phytoalexins belonging to the subclasses of the Pterocarpans and coumestans and by prenylation of the various isoflavonoids. The pterocarpan content stabilized at 2.24 mg of daidzein equivalents (DE) per g after 9 days. The levels of the less common glyceofuran, glyceollin IV, and V/VI ranged from 0.18 to 0.35 mg DE/g and were comparable to those of the more commonly reported glyceollins I, II, and III (0.22–0.32 mg DE/g) and glycinol (0.42 mg DE/g). The content of prenylated isoflavones after the induction process was 0.30 mg DE/g. The total isoflavonoid content increased by a factor of 10–12 on DW basis after 9 days, which was suggested to be ascribable to de novo synthesis. These changes were accompanied by a gradual increase in agonistic activity of the extracts toward both the estrogen receptor a (ERa) and ERs during the 10-day induction, with a more pronounced activity toward ERs. Thus, the induction process yielded a completely different spectrum of isoflavonoids, with a much higher bioactivity toward the estrogen receptors. This, together with the over 10-fold increase in potential bioactives, offers promising perspectives for producing more, novel, and higher potency nutraceuticals by malting under stressed conditions.
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Identification of prenylated Pterocarpans and other isoflavonoids in Rhizopus spp. elicited soya bean seedlings by electrospray ionisation mass spectrometry.
Rapid communications in mass spectrometry : RCM, 2010Co-Authors: Rudy Simons, Maxime C. Bohin, Tomas F. M. Kuijpers, Marian A. Verbruggen, Jean-paul Vincken, Harry GruppenAbstract:Phytoalexins from soya are mainly characterised as prenylated Pterocarpans, the glyceollins. Extracts of non-soaked and soaked soya beans, as well as that of soya seedlings, grown in the presence of Rhizopus microsporus var. oryzae, were screened for the presence of prenylated flavonoids with a liquid chromatography/mass spectrometry (LC/MS)-based screening method. The glyceollins I-III and glyceollidins I-II, belonging to the isoflavonoid subclass of the Pterocarpans, were tentatively assigned. The formation of these prenylated Pterocarpans was accompanied by that of other prenylated isoflavonoids of the subclasses of the isoflavones and the coumestans. It was estimated that approx. 40% of the total isoflavonoid content in Rhizopus-challenged soya bean seedlings were prenylated Pterocarpans, whereas 7% comprised prenylated isoflavones and prenylated coumestans. The site of prenylation (A-ring or B-ring) of the prenylated isoflavones was tentatively annotated using positive-ion mode MS by comparing the (1,3) A(+) retro-Diels-Alder (RDA) fragments of prenylated and non-prenylated isoflavones. Furthermore, the fragmentation pathways of the five Pterocarpans in negative-ion (NI) mode were proposed, which involved the cleavage of the C-ring and/or D-ring. The absence of the ring-closed prenyl (pyran or furan) gave exclusively -H(2) O(x,y) RDA fragments, whereas its presence gave predominantly the common RDA fragments.