RESUMO
1. In prior studies, it has been shown that tivantinib is extensively metabolized in humans to many oxidative metabolites and glucuronides. In order to identify the responsible enzymes, we investigated the in vitro metabolism of tivantinib and its four major circulating metabolites. 2. The primary isoforms involved in the elimination of tivantinib were CYP2C19 and CYP3A4/5. CYP2C19 showed catalytic activity for the formation of M5 (hydroxylated metabolite), but not for M4 (a stereoisomer of M5), whereas CYP3A4/5 catalyzed the formation of both metabolites. For the elimination of M4, M5 and M8 (keto-metabolite), CYP3A4/5 was the major cytochrome P450 isoform and UGT1A9 was mainly involved in the glucuronidation of M4 and M5. 3. ADH4 was identified as one of the major alcohol dehydrogenase isoforms contributing to the formation of M6 (sequential keto-metabolite of M4 and M5) and M8. The substrate preference of ADH for M4, and not M5, was observed in the formation of M6. 4. In conclusion, CYP2C19, CYP3A4/5, UGT1A9 and ADH4 were the primary drug metabolizing enzymes involved in the in vitro metabolism of tivantinib and its metabolites. The stereoselective hydroxylation by CYP2C19 and substrate stereoselectivity of ADH4-catalyzed oxidation in the in vitro metabolism of tivantinib was discovered.
Assuntos
Álcool Desidrogenase/metabolismo , Antineoplásicos/metabolismo , Citocromo P-450 CYP2C19/metabolismo , Pirrolidinonas/metabolismo , Quinolinas/metabolismo , Humanos , Hidroxilação , OxirreduçãoRESUMO
Glucose analogues 6, 12, 17b, 19a, and 19b of E5564 were synthesized, and their LPS-antagonistic activities were measured. The antagonistic activities (IC(50)) on LPS-induced TNFalpha production of these five compounds toward human whole blood were 72.8, 3.0, 0.9, 7.5, and 1.4nM, respectively. Inhibitory doses (ID(50)) of compounds 12, 17b, 19a, and 19b on TNFalpha production induced by co-injection of galactosamine and LPS in C3H/HeN mice in vivo were measured. The values of these compounds were 0.9, ND (not determined), 1.6, and 0.9mg/kg, respectively.
