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Elizabeth H Jeffery - One of the best experts on this subject based on the ideXlab platform.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
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studies on the toxic effects of crambe meal and two of its constituents 1 cyano 2 hydroxy 3 butene chb and epi progoitrin in broiler chick diets
British Poultry Science, 1996Co-Authors: P Kloss, Elizabeth H Jeffery, M E Tumbleson, Y Zhang, C M Parsons, M A WalligAbstract:Abstract 1. Studies were undertaken to determine a safe inclusion rate for crambe (Crambe abyssinica) meal in broiler chick diets, and to determine the mechanism for adverse effects by investigating its constituents; l‐cyano‐2‐hydroxy‐3‐butene (CHB) and 3‐butenyl glucosinolate (epi‐progoitrin, E‐PG). 2. Crambe meals were prepared to differ in E‐PG (19, 36 and 40 g/kg) and CHB contents (0.1, 0.7 and 1.9 g/kg), and with either active or inactive Thioglucosidase. 3. Meals were fed to 7‐d‐old broiler chicks at 50 or 100 g/kg of the diet for 12 or 13 d. In separate studies, isolated E‐PG or CHB were mixed into the diet or administered by gavage to 7‐d‐old broiler chicks in amounts equivalent to 50 or 100 g/kg crambe meal diets for 10 and 12 d, respectively. 4. Weight gain decreased (P<0.05) in chicks fed on the high glucosinolate crambe diets or isolated E‐PG. Food consumption decreased (P<0.05) in chicks fed on the diet containing the high E‐PG meal with active enzyme. 5. Mild liver lesions and increased seru...
Nathan V Matusheski - One of the best experts on this subject based on the ideXlab platform.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
L P Turtle - One of the best experts on this subject based on the ideXlab platform.
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effect of total intact glucosinolate intake from rapeseed meals with or without Thioglucosidase ec 3 2 3 1 or copper additions to the diet on the concentrations of 1 cyano 2 hydroxy 3 butene in the ileal digesta and faeces of growing pigs
Animal Feed Science and Technology, 1995Co-Authors: T L J Lawrence, T G Rowan, M R Preston, L P TurtleAbstract:Abstract Studies were made in pigs with cannulae sited near the terminal ileum of concentrations of the nitrile 1-cyano-2-hydroxy-3-butene (CHB) in ileal digesta and faeces consequent from varying daily total intact glucosinolate intakes induced by including in the diet rapeseed meals (200 g kg −1 ) of different total intact glucosinolate concentrations but of similar individual glucosinolate proportions with progoitrin predominating; a soyabean (SBM) based diet was used as the control. Ileal concentrations were determined from daily intakes (mmol × 10 3 ) of 3.5, 23.7 and 53.8, the latter with or without the addition of 200 mg kg −1 copper (Cu) to the diet. Ileal and faecal concentrations were determined, with or without the addition of Thioglucosidase (Thio) (EC 3.2.3.1) to the diet, from a daily intake of 46.6 × 10 3 mmol. No CHB was found either in ileal digesta from the SBM based diet or in faeces from this or from the rapeseed meal based diets. CHB was found in highly variable concentrations between individual animals in ileal digesta when daily total glucosinolate intake was 23.7 × 10 3 mmol or above with peak concentrations recorded at between 2.5 and 5.5 h after feeding. Within this 3 h period Thio and Cu additions gave inconsistent and very small effects. Whilst these experiments provide evidence of the production of CHB in the foregut of the pig, the significance of this finding relative to either deleterious effects in the animal and/or the production and absorption of CHB in other parts of the gut is not clear and awaits elucidation from further work.
John A Juvik - One of the best experts on this subject based on the ideXlab platform.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
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heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli
Phytochemistry, 2004Co-Authors: Nathan V Matusheski, John A Juvik, Elizabeth H JefferyAbstract:Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a Thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.
Johan Meijer - One of the best experts on this subject based on the ideXlab platform.
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characterization of a novel β Thioglucosidase cptgg1 in carica papaya and its substrate dependent and ascorbic acid independent o β glucosidase activity
Journal of Integrative Plant Biology, 2010Co-Authors: Han Nong, Johan Meijer, Jiaming Zhang, Meng Wang, Xuepiao Sun, Yun Judy Zhu, Qinhuang WangAbstract:Plant Thioglucosidases are the only known S-glycosidases in the large superfamily of glycosidases. These enzymes evolved more recently and are distributed mainly in Brassicales. Thioglucosidase research has focused mainly on the cruciferous crops due to their economic importance and cancer preventive benefits. In this study, we cloned a novel myrosinase gene, CpTGG1, from Carica papaya Linnaeus. and showed that it was expressed in the aboveground tissues in planta. The recombinant CpTGG1 expressed in Pichia pastoris catalyzed the hydrolysis of both sinigrin and glucotropaeolin (the only thioglucoside present in papaya), showing that CpTGG1 was indeed a functional myrosinase gene. Sequence alignment analysis indicated that CpTGG1 contained all the motifs conserved in functional myrosinases from crucifers, except for two aglycon-binding motifs, suggesting substrate priority variation of the non-cruciferous myrosinases. Using sinigrin as substrate, the apparent Km and Vmax values of recombinant CpTGG1 were 2.82 mM and 59.9 μmol min−1 mg protein−1, respectively. The Kcat/Km value was 23 s−1 mM−1. O-β-glucosidase activity towards a variety of substrates were tested, CpTGG1 displayed substrate-dependent and ascorbic acid-independent O-β-glucosidase activity towards 2-nitrophenyl-β-D-glucopyranoside and 4-nitrophenyl-β-D-glucopyranoside, but was inactive towards glucovanillin and n-octyl-β-D-glucopyranoside. Phylogenetic analysis indicated CpTGG1 belongs to the MYR II subfamily of myrosinases.
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research article characterization of a novel β Thioglucosidase cptgg1 in carica papaya and its substrate dependent and ascorbic acid independent o β glucosidase activity
2010Co-Authors: Han Nong, Johan Meijer, Jiaming Zhang, Meng Wang, Xuepiao Sun, Yun Judy Zhu, Qinhuang WangAbstract:Plant Thioglucosidases are the only known S-glycosidases in the large superfamily of glycosidases. These enzymes evolved more recently and are distributed mainly in Brassicales. Thioglucosidase research has focused mainly on the cruciferous crops due to their economic importance and cancer preventive benefits. In this study, we cloned a novel myrosinase gene, CpTGG1, from Carica papaya Linnaeus. and showed that it was expressed in the aboveground tissues in planta. The recombinant CpTGG1 expressed in Pichia pastoris catalyzed the hydrolysis of both sinigrin and glucotropaeolin (the only thioglucoside present in papaya), showing that CpTGG1 was indeed a functional myrosinase gene. Sequence alignment analysis indicated that CpTGG1 contained all the motifs conserved in functional myrosinases from crucifers, except for two aglycon-binding motifs, suggesting substrate priority varia- tion of the non-cruciferous myrosinases. Using sinigrin as substrate, the apparent K m and V max values of recombinant CpTGG1 were 2.82 mM and 59.9 µmol min −1 mg protein −1 , respectively. The K cat/K m value
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myrosinase gene family evolution and herbivore defense in brassicaceae
Plant Molecular Biology, 2000Co-Authors: Lars Rask, Erik Andreasson, Barbara Ekbom, Susanna Eriksson, Bo Pontoppidan, Johan MeijerAbstract:Glucosinolates are a category of secondary products present primarily in species of the order Capparales. When tissue is damaged, for example by herbivory, glucosinolates are degraded in a reaction catalyzed by Thioglucosidases, denoted myrosinases, also present in these species. Thereby, toxic compounds such as nitriles, isothiocyanates, epithionitriles and thiocyanates are released. The glucosinolate-myrosinase system is generally believed to be part of the plant's defense against insects, and possibly also against pathogens. In this review, the evolution of the system and its impact on the interaction between plants and insects are discussed. Further, data suggesting additional functions in the defense against pathogens and in sulfur metabolism are reviewed.
