20（S）-原人参三醇及其ocotillol型差向异构体代谢物的排泄

目的：考察20（S）-原人参三醇（PPT）及其ocotillol型差向异构体代谢物（简称为M1、M2）在尿液、粪便中的排泄情况和两代谢物在胆汁中的排泄情况。方法采用LC-MS/MS法分别测定大鼠尿液、粪便样品和其经葡萄糖醛酸酶水解后PPT、M1和M2的浓度，以及大鼠胆汁样品和其经葡萄糖醛酸酶水解后M1和M2的浓度。结果灌胃给予PPT后72 h，PPT、M1和M2的粪便累积排泄量分别为给药剂量的14.88%、1.34%和0.084%，经酶水解后，其累积排泄量分别为14.77%、1.36%和0.085%，它们基本不经尿排泄；灌胃给予M1或M2后72 h粪便累积排泄量分别为给药剂量的4.41%、47.20%，基本不经尿排泄。灌胃给予M1或M2后36 h胆汁累积排泄量分别为给药剂量的3.01%和0.068%，静注给药M1、M2后36 h，其胆汁累积排泄量分别为给药剂量的8.80%、1.24%。结论灌胃给予PPT后，PPT及其代谢物M1、M2少量经粪便排泄，基本不经尿排泄；M1和M2在大鼠的胆汁排泄具有立体选择性差异。

Excretion of 20(S)-protopanaxatriol and its ocotillol type epimers metabolites in rats

Objective To explore the excretion of the 20(S)-protopanaxatriol(PPT)and its metabolites ocotillol type epi?mers(M1 and M2)in urine,feces samples and the excretion of M1 and M2 in bile samples. Methods The concentration of PPT,M1 and M2 in urine,feces samples and the concentration of M1 and M2 in bile samples were determined by the LC-MS/MS methods with or without the hydrolization byβ-glucuronidase. Results After intragastric(ig)administration of PPT,the cumulative excretion rate for 72 h of PPT,M1 and M2 in feces were 14.88%,1.34%and 0.084%,respectively. With the hydrolization byβ-glucuronidase,the cumulative excretion rate for 72 h of PPT,M1 and M2 in feces were 14.77%,1.36%and 0.085%,respectively. However,the epimers and PPT were hardly detected in urine. After ig administration of M1 or M2,the accumulation excretion rate were 4.41%for M1 and 47.2%for M2 in feces,while both epimers were hardly detected in urine. After ig administration of M1 or M2,the 36 h cumulative bili?ary excretion rate was 3.01%for M1,and only 0.068%for M2. The 36 h cumulative biliary excretion rate of M1 was 8.80%after intra?venous administration ,while only 1.24%for M2. Conclusion After ig administration of PPT,a small amount of PPT and its metabo?lites(M1,M2)are excreted by the feces but little via urine ,and there are stereoselectivity differences in biliary excretion between M1 and M2.