两色金鸡菊提取物中3种黄酮苷在大鼠胃肠道的水解代谢研究

Hydrolysis of three flavonoid glycosides from capitula of Coreopsis tinctoria in rat gastrointestinal tracts

目的研究两色金鸡菊(CCT)中马里苷(CCT-1)、异奥卡宁-7-O-β-D-吡喃葡萄糖苷(CCT-2)和花旗松素-7-O-β-D-吡喃葡萄糖苷(CCT-3)在大鼠胃肠道内是否发生水解代谢。方法采用体外孵育法,筛选底物质量浓度、酶质量浓度及孵育时间,再通过测定的苷元质量浓度分析3种黄酮苷在大鼠胃肠道的水解代谢程度。结果孵育体系中,质量浓度为36μg·mL-1的黄酮苷与蛋白质量浓度为1.5mg·mL-1的组织提取物孵育45min,发现CCT-1、CCT-2和CCT-3的水解代谢率在大鼠十二指肠中依次为4.8%,7.1%和0%;在空肠中依次为61.8%,35.3%和13.7%;在回肠中依次为64.8%,29.7%和20.5%;在胃、结肠和盲肠组织提取物中无水解。结论 CCT-1、CCT-2和CCT-3在大鼠小肠中均发生去糖基水解代谢,生成苷元,三者水解程度依次为:CCT-1>CCT-2>CCT-3。此3种黄酮苷及其苷元可能是两色金鸡菊潜在的药效物质基础。

Objective To study the hydrolysis of marein （CCT-1）,flavanomarein （CCT-2） and taxifolin-7-O-β-D-glucopyranoside （CCT-3） from capitula of Coreopsis tinctoria （CCT） in rat gastrointestinal tracts （GIT）. Methods Substrate concentration,enzyme concentration and incubating time were optimized by incubation in vitro ,and the hydrolyzation ratio was determined for evaluating whether CCT-1,CCT-2 and CCT-3 were hydrolyzed in GIT. Results After 36μg·m^-1of flavonoid glycosides being added to cell-free extract （1.5 mg·mL^-1of protein） and incubated for 45 min,the hydrolyzation ratio of CCT-1,CCT-2 and CCT-3 were 4.8%,7.1% and 0% in duodenum,61.8%,35.3% and 13.7% in jejunum,64.8%,29.7% and 20.5% in ileum,respectively,while there was no hydrolyzation happened in stomach,colon and cecum. Conclusion CCT-1,CCT-2 and CCT-3 could be hydrolyzed only in rat small intestine （duodenum,jejunum and ileum） cell-free extract,the hydrolyzation extent order was：CCT-1〉CCT-2〉CCT-3.The results will help us to clarify the real functional components of CCT in vivo.