Identification of metabolites of antitumor lead compound T-OA in rat urine by HPLC-HRMS

Abstract

To study the major metabolites of antitumor lead compound T-OA (oleanolic acyl-3, 5, 6-trimethyl pyrazine-2-methyl ester) in rat urine, in order to preliminarily infer its metabolic mode in rats. Rat urines of the blank group, the raw material group (ligustrazine TMP and oleanolic acid OA Moore equivalent) and the T-OA group were collected and freeze-dried; Solids were extracted by ethyl acetate; And then the extracts were re-dissolved with acetonitrile. HPLC-HRMS coupling technique was adopted to find the potential mass spectrum peak under ESI(+) (see symbol) ESI(-) modes. Metabolite-related information was obtained by comparing the three groups of spectra. One metabolite of OA and two metabolites of TMP were identified in the raw material group; none metabolite of T-OA but one phase II metabolite was detected in the T-OA group. It is the first time to identify one phase II metabolite of T-OA and one phase II metabolite of OA were identified in rat urine. On that basis, the researchers preliminarily inferred that T-OA does not show the efficacy in the form of raw material. The HPLC-HRMS method established could be used to identify metabolites of related derivative structures. This paper could also provide certain reference for designing pro-drugs based on oleanolic acid.