大鼠肠内菌对黄山药总皂苷代谢及代谢产物鉴定

目的 :观察大鼠肠内菌离体对黄山药总皂苷 (TSDP)的代谢及整体给予TSDP后吸收入血成分鉴定。方法 :用薄层色谱 (TLC)及电喷雾质谱 (ESI-MS)法检测离体肠内菌对TSDP的代谢产物。给大鼠igTSDP 900mg·kg^-1,于给药后不同时间采集尿及血样品 ,用ESI-MS检测吸收入血成分。结果 :TSDP容易被大鼠消化道菌群代谢 ,随着代谢时间的延长 ,出现了各种甾体皂苷的降解产物及终产物薯蓣皂苷元 (Dio)。整体实验表明 ,在大鼠血及尿中均发现分子量为 415 .3(amu)的代谢产物 ,经ESI MS二级质谱分析 ,上述分子量的单体化合物为Dio。结论 :TSDP可被大鼠肠内菌代谢 ,大鼠igTSDP后Dio被吸收入血中。

Intestinal Bacteria Metabolism of TSDP and Characterization of Metabolites in Rats

Objective: To study the rat intestinal bacteria metabolism of total saponins of dioscorea pathaica (TSDP ) in vitro, and characterize the metabolites in serum and urine of rats after oral administration of TSDP 900 mg·kg^-1 . Method:TSDP metabolites were detected with thin layer chromatography (TLC) and combination of electrospray ionization mass spectrometry (ESI-MS) and sequential tandem mass spectrometry (MS n). Result: In vitro, TSDP was decomposed easily by rat intestinal bacteria, and metabolites DP-1, DP-2, DP-4, DP-5 and diosgenin (Dio) were observed with prolongation of incubation time by ESI-MS₂. In-vivo , in the full scan positive mass spectrum of the rat urine sample, the ion peak at m/z 415 (M H) and its characteristic fragmen ions at m/z 397 and m/z 271 in the MS/MS spectrum were identified with that of metabolite Dio, therefore metabolite Dio was deduced to exist in the rat urine,and metablite Dio was allso detected in the rat serum sample. Conclusion: TSDP is decomposed easily by rat intestinal bacteria and metabolite diosgenin is absorbed into blood after oral administration of TSDP.