灰色链霉菌对芦丁的生物转化及产物的抗氧化活性

Biotransformation of Rutin by Streptomyces griseus and Antioxidation of Metabolites

目的:研究灰色链霉菌对芦丁的生物转化及其产物对超氧阴离子(O2·-)的清除能力变化。方法:用标准马铃薯培养基培养的灰色链霉菌中加入底物后继续培养4天,发酵液经萃取后采用硅胶柱层析分离纯化,产物的结构根据光谱数据予以鉴定。通过化学发光法测定转化产物对邻苯三酚-鲁米诺-碳酸缓冲液(pH10.2)体系产生的O2·-的清除能力。结果:分离鉴定了6个代谢产物,分别是槲皮素3OβD葡萄糖苷、槲皮素、山柰酚3OβD芸香糖苷、异鼠李素、异鼠李素3O葡萄糖苷和山柰酚,其中4个化合物的抗氧化活性比底物芦丁强。结论:此转化过程涉及到3类反应即糖苷水解、甲基化和去羟基化反应,其中苷类的去羟基化反应为首次发现。本研究表明微生物转化是增加天然化合物多样性的有效方法。

AIM： To investigate the biotransformation of rutin by Streptomyces griseus, and the scavenging activity change of the metabolites of superoxide anion（O2^-） radicals. METHODS： Substrate was added into the culture of Streptomyces griseus and then incubated for 4 d, The culture was extracted and then subjected to silica gel chromatography. Antioxidant activities of the metabolites were compared by scavenging the superoxide anion （O2^-） radicals generated by the PyTogallic acid-3-Amino-phthalhydrazid （Luminol）-Na2CO3/NaHCO3 buffer （pH 10.2） system. RESULTS： Six metabolites were isolated and their structures were identified as quercetin-3-O-β-D-glucoside, querectin, kaempferol-3-O-β-D-rutinoside, isorhamnetin, isorhamnetin-3-O-β-D-glucoside and kaempferol on the basis of spectroscope data. Four of them have better antioxidant activity than rutin. CONCLUSION： There are three types of reaction in this transformation, i.e, deglycosylation, methylation and dehydroxylation. Dehydroxylation of glycoside has been found for the first time by microoganism. This study pruves that microbial transformation is a useful way to increase the diversity of the natural products.