College of Pharmacy, Jilin University, Changchun, 130021, China.
China-Japan Union Hospital, Jilin University, Changchun, 130021, China.
Biomed Chromatogr. 2020 Aug;34(8):e4856. doi: 10.1002/bmc.4856. Epub 2020 Jun 16.
Ocotillol, pseudo-ginsenoside RT5 (RT ), and pseudo-ginsenoside F (PF ) are ocotillol-type saponins that have the same aglycone structure but with different numbers of glucose at the C-6 position. In this study, the metabolites of ocotillol, RT , and PF in rat plasma, stomach, intestine, urine, and feces after oral administration were investigated by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry. The results showed that RT was easily biotransformed into metabolites in vivo, whereas PF and RT were difficult to be biotransformed. Hydrogenation, dehydrogenation, dehydration, deglycosylation, deoxygenation, hydration, phosphorylation, deoxidation, glucuronidation, and reactions combining amino acid were speculated to be involved in the biotransformation of ocotillol, RT , and PF . Based on the structural analysis of metabolites, it was deduced that hydrogenation, dehydration, deoxidation, and reactions combining amino acid occurred on the aglycone structure, whereas deglycosylation, hydration, and phosphorylation occurred on the glycosyl chain. Further, metabolites in plasma, urine, feces, and tissues were different: First, glucuronidation products were found in urine, stomach, intestine, and feces, but not in plasma. Second, the ocotillol prototype was not identified in urine samples. Third, the RT prototype was found in stomach, intestine, feces, and urine, but not in plasma.
竹节人参皂苷元 O、伪人参皂苷 RT5（RT）和伪人参皂苷 F（PF）均属于竹节人参皂苷元型皂苷，它们具有相同的苷元结构，但在 C-6 位上的葡萄糖数量不同。本研究采用超高效液相色谱-飞行时间质谱法研究了竹节人参皂苷元 O、RT 和 PF 在大鼠口服给药后的血浆、胃、肠、尿和粪便中的代谢产物。结果表明，RT 易在体内发生生物转化，而 PF 和 RT 则不易发生生物转化。推测竹节人参皂苷元 O、RT 和 PF 的生物转化涉及加氢、脱氢、脱水、去糖、脱氧、水合、磷酸化、脱氧、葡萄糖醛酸化以及与氨基酸结合的反应。基于代谢产物的结构分析，推断苷元结构上发生了加氢、脱水、脱氧和与氨基酸结合的反应，而糖苷链上发生了去糖、水合和磷酸化反应。此外，血浆、尿液、粪便和组织中的代谢产物不同：首先，在尿液、胃、肠和粪便中发现了葡萄糖醛酸化产物，但在血浆中未发现；其次，原型竹节人参皂苷元在尿液样本中未被鉴定；最后，原型 RT 在胃、肠、粪便和尿液中被发现，但在血浆中未被发现。
