罗汉果皂苷V在人工胃液中的稳定性和体外代谢研究

为了研究罗汉果皂苷V在胃肠道中的稳定性及体外代谢特征,该研究首先考察罗汉果皂苷V在人工胃液中的稳定性,然后在体外模拟人肠内环境,研究人肠内细菌对该成分的代谢作用,并采用LCMS/IT-TOF液质联用仪分析了培养液中的化学成分,考察了罗汉果皂苷V在人工胃液和人肠道菌群培养液中的变化。结果表明:罗汉果皂苷V在人工胃液条件下,迅速发生酸水解反应,分别脱去3个糖苷、4个糖苷、5个糖苷及2个氢转化为二糖苷、一糖苷与脱氢苷元,其脱糖反应随着时间的延长而反应越完全,反应4 h后就只剩下苷元; 该化合物在人的肠道菌群作用下经过脱糖反应转化为四糖苷、三糖苷、二糖苷、一糖苷,经过糖苷化反应转化成六糖苷。通过体外实验,初步了解罗汉果皂苷V在胃液和肠道环境中的降解规律,该研究结果为今后探讨罗汉果皂苷在人体内的代谢与生物转化规律提供了物质和技术基础。

Stability of mogroside V in artificial gastric juice and its metabolism in vitro

In order to evaluate the stability of mogroside V in gastrointestinal tract and study its in vitro metabolism, mogroside V was incubated with artificial gastric juice and human intestinal bacteria, and a liquid chromatography/mass spectrometry method by LCMS/IT-TOF was applied to analyze the products of mogroside V in artificial gastric juice and human intestinal bacteria culture medium. The results indicated that mogroside V was degraded quickly in artificial gastric juice to be secondary glycosides with two glycosyls or one glycosyl and mogrol without glycosyl. And the longer time it was incubated, the more completely it was degraded, its product was mogrol while the incubation time was 4 h. While in culture medium of human intestinal bacteria, mogroside V was transformed to mogroside IV(isomer)mogroside III(isomer), mogroside II(isomer)and mogroside I(isomer)by deglycosylation reaction, as well as to glycoside with six glycosyls,by glucosylation reaction. Therefore, a general knowledge on the degradation of mogroside V was obtained after this experiment, which would shed light on the further exploitation of mogroside V and Siraitia grosvenorii.