The metabolites and biotransformation pathways in vivo after oral administration of ocotillol, RT 5 , and PF 11

• Published in: Biomedical chromatography 2020-08, Vol.34 (8), p.e4856
• Main Authors: Liu, Jihua, Gan, Huizhu, Li, Ting, Wang, Jia, Du, Guangguang, An, Yang, Yan, Xiaojing, Geng, Cong
• Format: Article
• Language: English
• Subjects: Administration, Oral; Animals; Biotransformation; Chromatography, High Pressure Liquid; Feces - chemistry; Female; Ginsenosides - administration & dosage; Ginsenosides - analysis; Ginsenosides - chemistry; Ginsenosides - pharmacokinetics; Intestines - chemistry; Mass Spectrometry; Rats; Rats, Sprague-Dawley; Stomach - chemistry; Tissue Distribution
• ISSN: 0269-3879; 1099-0801
• DOI: 10.1002/bmc.4856

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.