Abstract:The metabolism of marein in Coreopsis tinctoria Nutt. was investigated by research of intestinal flora, and the mechanisms of marein metabolism was explored in this study as well as the relationship between its prototypical components and metabolic products. Fresh feces from healthy Sprague-Dawley rats were collected to prepare an intestinal bacterial culture solution. An in vitro incubation model of rat intestinal flora was then established, and marein monomer was inoculated into this model and cultured under anaerobic conditions. Metabolites at 0, 6, 12, 24, and 36 hours were qualitatively analyzed using Ultrahigh Performance Liquid Chromatography Tandem Quadrupole Time-of-flight Mass Spectrometry (UHPLC-Q-TOF-MS/MS). The external standard method was used to determine marein content and levels of its four main metabolites - flavanomarein, isookanin, isochlorogenic acid B, and okanin - at different incubation times. This allowed characterization of marein metabolism in rat intestinal bacterial culture solution. Eleven metabolites were identified in rat intestinal flora cultured with marein. During marein metabolism by rat intestinal flora, reactions including isomerizations, glucuronidation, ring cleavage, hydroxylation, and acetylation were prominent. Under the action of rat intestinal flora, the prototype components of marein became undetectable by 6 hours. Between 12 to 24 hours, detectable primary marein metabolic products were isookanin, okanin, 7,3′,5′-trihydroxyflavone, quercetin, and other genins. In conclusion, intestinal flora accelerates the hydrolysis and deglycosylation of marein, with all late-stage metabolic products being genins.
