Identification of the metabolites of methylophiopogonanone A by ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry

Rationale Methylophiopogonanone A (MOA) is a naturally occurring homoisoflavonoid from the Chinese herb Ophiopogon japonicus, which has been demonstrated to attenuate myocardial apoptosis. However, the metabolism of MOA remains unknown. The goal of the present work was to investigate the in vitro metabolism of MOA using liver microsomes and hepatocytes. Methods The metabolites were generated by incubating MOA with rat, monkey and human liver microsomes or hepatocytes. The resulting samples were analyzed by using a quadrupole-orbitrap high-resolution mass spectrometer. The metabolites were identified through the measurements of the exact mass, elemental composition and product ions. Results A total of 15 metabolites were detected and identified. Among these metabolites, M7 (demethylenation) was the most abundant metabolite in liver microsomes, while M6 (hydroxylation) was the predominant metabolite in hepatocytes, and glucuronidation metabolites (M9 and M10) were also the main metabolites in hepatocytes. The metabolic pathways of MOA included hydroxylation, demethylenation, glucuronidation, methylation, sulfation and glutathione conjugation. Conclusions This study for the first time provides valuable data on the metabolites of MOA, which will be of great importance for a better understanding of its disposition and to predict human pharmacokinetics.