摘要：Icaritin (IT) was the main product of intestinal metabolism of main flavonoid compounds in Epimedium. Our previous study of the intestinal metabolites of IT was mainly focused on detecting the metabolites in rat faeces, which did not directly reacted and premeditate the complex environment of small bowel. Therefore, in this paper, the contents of small bowel were collected and analyzed by ultra performance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC-Q-TOF/ MS), and then the main metabolites and metabolic pathways of IT in rats small bowel were explained clearly. Finally, six major metabolites were found in rats small bowel after oral administration of IT, which were m/z 367.1187, 383.1125, 545.1678, 559.1448, 561.1610, and 721.1979, respectively. These six metabolites and their chemical structures were firstly discovered and identified by us. The metabolites m/z 559.1448 and 545.1678 were the combinations of m/z 383.1125 and 369.1308 (IT) linked with one glucuronic acid, respectively. In the intestinal contents, the IT prototype had the highest peak areas, which indicated that IT mainly existed in the form of prototype. Meanwhile, our results further confirmed that the bioavailability of IT might be low, and subsequent research would likely focus on improving the biopharmaceutical properties and enhancing the bioavailability of IT. This study was useful and complementary to our previous findings.
关键词：metabolites; small bowel; icaritin; glucuronidation; UPLC-Q-TOF/MS
