排序方式: 共有34条查询结果,搜索用时 15 毫秒
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生物转化生产熊果苷的研究进展 总被引:1,自引:0,他引:1
熊果苷是一种天然存在的糖苷类物质,具有多种生理活性,近年来作为美白添加剂广泛用于化妆品中。介绍了植物细胞组织、微生物和酶3种利用生物转化制备熊果苷的方法,其中以植物器官培养和与酶工程相联系的转基因微生物生产熊果苷或其活性衍生物的方法是未来的主要发展方向。 相似文献
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This study reports that earthworms, Allolobophora chlorotica, are capable of biotransforming paraquat, a toxic herbicide, resulting in the formation of reactive oxygen species (ROS). We found that in earthworms the reduction of paraquat is mediated by NADPH- and NADH-cytochrome c reductase activities. The formation of superoxide anion (O2−) from the incubation of paraquat with the earthworm extracts was demonstrated by using both Cypridina luciferin analog (CLA) chemiluminescence and the SOD-inhibitable cytochrome c reduction reaction. In addition, in vivo exposure of earthworms to paraquat in solution (24 and 48 h) was performed to investigate whether or not the herbicide affects the levels of the NAD(P)H-cytochrome c reductase activities. Although in vitro NADPH-cytochrome c reductase reduces paraquat more easily than the NADH-dependent activity, after the in vivo exposure an increase of NADH-cytochrome c reductase activity(s) by 12% compared to control values was observed, whereas NADPH-cytochrome c reductase activity was not affected. Xanthine oxidase (XO) is an enzyme implicated in paraquat toxicity, however, no XO was detected in earthworm extracts nor hypoxanthine was a source of electrons for the herbicide reduction. For comparative reasons menadione, a redox cycling quinone, was also incubated with the earthworm extracts. It was found that the incubation of menadione with earthworm extracts formed about two times more (O2−) than with paraquat. It is concluded that the exposure of paraquat to earthworms could elicit radical formation and consequently toxic effects via oxidative stress-mediated mechanisms. The reduction of paraquat by the reductases leads to the formation of paraquat radical, which reacts with molecular oxygen, accounting for the formation of superoxide anion. Further studies are required to conclude that the observed increase of NADH-cytochrome c reductase activity(s) should be used as a biomarker for paraquat exposure in earthworms. 相似文献
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Kraisiri Khidkhan Saranya Poapolathep Sittinee Kulprasertsri Rattapong Sukkheewan Paphatsara Khunlert Mario Giorgi Amnart Poapolathep 《Journal of veterinary science (Suw?n-si, Korea)》2022,23(6)
Domestic poultry are among the non-target species of exposure to fipronil, but limited information is available on the metabolic effects of fipronil exposure in avian. We investigated the comparative capacity of in vitro biotransformation of fipronil among chicken, duck, quail, goose, and rat. Interspecies differences in kinetic parameters were observed; the clearance rate calculations (Vmax/Km) indicated that chicken and duck are more efficient in the cytochrome P450-mediated metabolism of fipronil to sulfone than quail, goose and rat. The lower hepatic clearance of fipronil in quail, goose and rat, suggested that fipronil sulfone may serve as a biomarker to indicate fipronil exposure in these species. 相似文献