Structure activity relationship of human microsomal epoxide hydrolase inhibition by amide and acid analogues of valproic acid.

Citation:

O Spiegelstein, Kroetz, DL, Levy, RH, Yagen, B, Hurst, SI, Levi, M, Haj-Yehia, A, ו Bialer, M. 2000. “Structure Activity Relationship Of Human Microsomal Epoxide Hydrolase Inhibition By Amide And Acid Analogues Of Valproic Acid.”. Pharmaceutical Research, 17, 2, Pp. 216–221. doi:10.1023/a:1007577600088.

תקציר:

PURPOSE: The purpose of this study was to evaluate the in vitro inhibitory potency of various amide analogues and derivatives of valproic acid toward human microsomal epoxide hydrolase (mEH). METHODS: mEH inhibition was evaluated in human liver microsomes with 25 microM (S)-(+)-styrene oxide as the substrate. Inhibitory potency expressed as the median inhibitory concentration (IC50) was calculated from the formation rate of the enzymatic product, (S)-(+)-1-phenyl-1,2-ethanediol. RESULTS: Inhibitory potency was directly correlated with lipophilicity and became significant for amides with a minimum of eight carbon atoms. Branched eight-carbon amides were more potent inhibitors than their straight chain isomer, octanamide. N-substituted valproylamide analogues had reduced or abolished inhibition potency with the exception of valproyl hydroxamic acid being a potent inhibitor. Inhibition potency was not stereoselective in two cases of chiral valpromide isomers. Valproyl glycinamide, a new antiepileptic drug currently undergoing phase II clinical trials and its major metabolite valproyl glycine were weak mEH inhibitors. Acid isomers of valproic acid were not potent mEH inhibitors. CONCLUSIONS: The structural requirements for valproylamide analogues for potent in vitro mEH inhibition are: an unsubstituted amide moiety; two saturated alkyl side chains; a minimum of eight carbons in the molecule.