Metabolite profiling of anhuienoside C by rat intestinal bacteria using the LC-MS metabolomic approach.

1.Anhuienoside C (A-C) is the main active component of the saponin exact of "Di Wu", an oral drug for rheumatism treatment in China. In this study, we aimed to elucidate the metabolic pathways of A-C by intestinal bacteria using the metabolomic approach. 2.Four deglycosylated metabolites (M1, M2, M3 and M4) were identified after A-C (50 µM) was incubated with rat fecal lysate. Chemical structures of these metabolites were determined by high-resolution masses and nuclear magnetic resonance (NMR). 3.A one-compartment pharmacokinetic model was used to describe the formation of bacterial metabolites at a dose of 10 µM A-C. The results revealed that formation of M1 and M2 was rapid, whereas formation of M3 was rather slow. Further, it was found that the metabolites were generated by successive cleavage of the glycosyl residues. 4.This is the first report that A-C is subjected to efficient bacterial metabolism in the gut with M1 and M2 as main metabolites. Our study should be helpful for a better understanding of in vivo disposition of oral A-C.