Metabolism of sennosides by intestinal flora.
作者:MASAO HATTORI、GAKUSEN KIM、SAYURI MOTOIKE、KYOICHI KOBASHI、TSUNEO NAMBA
DOI:10.1248/cpb.30.1338
日期:——
Through investigation of the metabolism of sennosides by intestinal contents and feces of the rat, the main metabolic pathways were elucidated and found to be quite different from those previously proposed on the basis of the metabolites produced by individual strains isolated from the human intestine. Sennoside A was hydrolyzed in a stepwise fashion to produce sennidin A via sennidin A-8-monoglucoside by β-glucosidase present in the intestinal contents and feces, and sennoside B to sennidin B via sennidin B-8-monoglucosides in a similar way. The resulting metabolites, sennidins A and B, were interconvertible under the experimental conditions used, and were further reduced to give rheinanthrone, a purgative active principle of Rhei Rhizoma and senna, possibly by reductase bound to cell membranes of intestinal bacteria.
通过研究大鼠肠道内容物和粪便中番泻苷的代谢过程,揭示了其主要的代谢途径,并发现这些途径与之前基于从人类肠道分离出的各个菌株所产生的代谢物而提出的途径大相径庭。番泻苷A通过肠道内容物和粪便中的β-葡萄糖苷酶逐步水解,先形成番泻双蒽酮A-8-单葡萄糖苷,再转化为番泻双蒽酮A;番泻苷B也以类似方式通过番泻双蒽酮B-8-单葡萄糖苷转化为番泻双蒽酮B。在实验条件下,所得代谢物番泻双蒽酮A和B可相互转化,并进一步被还原,可能通过肠道细菌细胞膜上的还原酶,生成大黄泻素蒽酮,这是大黄根茎和番泻叶的泻下活性成分。