Studies On In Vitro And In Vivo Biotransformation Of Butyl Phthalide And Its Analogues

The biotransformation of butyl phthalide and its analogues was studied. First, the in vitro metabolism of 6-chloro butyl phthalide was investigated and a HPLC method for the study of the in vitro metabolism of butyl phthalide analogues was developed. Thus, the primary profiles of their biotransformation in vitro were discussed. Then, a more sensitive and convenient gas chromatography-mass spectrometric (GC/MS) method was established for the study of the in vitro and in vivo metabolism of butyl phthalide (HBP), 6-CH₃O-HBP,6-OH-HBP and 6-Cl-HBP.1. The in vitro metabolism of 6-CI-HBP(CBP) was studied by rat hepatic microsomes. The constitution of the incubation system was optimized and a RP-HPLC-DAD method was developed for the on-line analysis of CBP and its four metabolites. The difference of the metabolism profiles of CBP by rat liver microsomes induced by PB and 3-MC was also compared. TLC, column chroma-tography,and p(?)eparative HPLC were used for the isolation and purification of the major metabolites and they were identified as y -hydroxyl-CBP and β -hydroxy-CBP by UV, NMR and MS.2. The in vitro metabolites of HBP by rat liver microsomes were determined by GC/MS and GC/MS with TMS dcrivatization.The chemical structures of six metabolites were identified by comparing the EI/MS data. Three major metabolites were identified as 3-0H-HBP,γ -OH-HBP and a hydroxylate on its benzene ring.3. The in vitro biotransformation of 6-CH3-HBP(MBP) and 6-OH-HBP(HyBP) by rat liver microsomes was investigated by the developed GC/MS method. Three major metabolites of MBP were identified as 3-OH-MBP, 6-OH-HBP , γ-OH-MBP and a less polar metabolite which was tentatively identified as an oxolation product. No metabolite was detected in the extract of HyBP after incubation with rat liver microsomes.