大鼠肠道菌群对紫丁香苷体外代谢转化研究

目的观察大鼠肠道菌群对紫丁香苷的体外代谢转化作用。方法将紫丁香苷与离体大鼠肠道菌群的孵育液分别培养O、4、8、12、24、48 h后取样,经正丁醇萃取后采用HPLC和LC-MS法对代谢产物进行定性和定量分析;扩大培养24h的孵育液经正丁醇萃取后,采用ODS柱色谱和重结晶方法分离制备代谢产物NMR法鉴定其结构。结果大鼠肠道菌群对紫丁香苷具有显著的代谢转化作用。在0~48 h代谢组的孵育液中共检测到2个代谢产物芥子醇(M_1)和右旋丁香树脂酚(M_2)。12h时有81%的紫丁香苷被代谢转化,24 h时紫丁香苷已经完全被代谢转化;并且检测到12h之前的主要代谢产物为M_1,24h后的主要代谢产物为M2,且24h后未能检测到M_1。结论在离体条件下,大鼠肠道菌群可以在24h内将紫丁香苷完全代谢转化为M_1,然后再将M_1代谢转化为M_2,且8~12h内转化紫丁香苷的速率最快。

In vitro metabolic transformation of syringin by rat intestinal flora

Objective To study the in vitro metabolic transformation of syringin by rat intestinal flora in vitro. Methods When syringin was incubated for 0, 4, 8, 12, 24, and 48 h with rat intestinal flora in vitro, the incubation medium was respectively extracted with n-BuOH, and then HPLC and LC-MS were applied for the qualitative and quantitative analysis of the metabolites. The metabolites were extracted with n-BuOH, isolated by ODS column chromatography, and recrystallization from the extended medium after 24 h of incubation, and their structures were determined on the basis of the NMR experiments. Results Syringin could be easily metabolized by rat intestinal flora in vitro. About 81% of the syringin was metabolized at 12 h, and it was completely metabolized at 24 h. Two metabolites, sinapyl alcohol (M₁) and (+)-syringaresinol (M₂), in the incubation medium of experimental group were identified within 48 h. The major metabolite was M₁ during the first 12 h, and M₂ was the only metabolite identified after 24 h. Conclusion In vitro, syringin could be completely metabolized to M₁, and then converted into M₂ by rat intestinal flora within 24 h, and the metabolism of syringin to M₁ is proceeded most rapidly in 8~12 h.