Metabolism study has been carried out on 1-hydroxy-2,3,5-trimethoxyxanthone （HM-1） and 1-hydroxy-2,3,4,7- tetramethoxyxanthone （HM-2）, which are two biologically active ingredients isolated from the Tibetan herb, Halenia elliptica D. Don., in rat liver microsomes in vitro. A method of high performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry （LCMSn-ESI-IT-TOF） was applied to analyze metabolites of HM-1 and HM-2 on line, and five metabolites were identified containing 1,5-dihydroxy-2,3-dimethoxyxanthone （HM-5）, 1,7-dihydroxy-2,3,4-trimethoxyxanthone （HM-9）, 1,4, 7- trihydroxy-2,3-dimethoxyxanthone （HM-10）, 1,4-dihydroxy-2,3,7-trimethoxyxanthone （HM-11） and 1,2-dilaydroxy-3,4,7- trimethoxyxanthone （HM-12）. Among these metabolites, HM-9, HM-11, and HM-12 were isomers mutually. The results indicated that HM-1 and HM-2 occurred Phase I metabolic reaction of demethylation in rat microsomes in vitro.
Ru FengJian Gong ShiXiao Wei LiuChun Tao CheJohn H.K. YeungYan Wang
