1-phenylpropene and cinnamyl-alcohol

Pyrolytic products of smoked methamphetamine hydrochloride are well established. Among the various degradation products formed, trans-phenylpropene (trans-beta-methylstyrene) is structurally similar to styrene analogues known to be bioactivated by CYP enzymes. In human liver microsomes, trans-phenylpropene was converted to the epoxide trans-phenylpropylene oxide (trans-2-methyl-3-phenyloxirane) and cinnamyl alcohol. Incubation of trans-phenylpropene with microsomes in the presence of enzyme-specific P450 enzyme inhibitors indicated the involvement of CYP2E1, CYP1A2, and CYP3A4 enzymes. Both (R,R)-phenylpropylene oxide and (S,S)-phenylpropylene oxide were formed in human liver microsomal preparations. Enantiomers of trans-phenylpropylene oxide were stereoselectively and regioselectively conjugated in a Phase II drug metabolism reaction catalyzed by human liver cytosolic enzymes consisting of conjugation with glutathione. The structure of the phenylpropylene oxide-glutathione adduct is consistent with nucleophilic ring-opening by attack at the benzylic carbon. Exposure of cultured C6 glial cells to (S,S)-phenylpropylene oxide produced a cytotoxic response in a concentration-dependent manner based on cell degeneration and death.

Topics: Alkenes; Animals; Binding Sites; Cattle; Cell Line, Tumor; Cell Size; Cell Survival; Chromatography, Liquid; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Cytosol; Enzyme Inhibitors; Epoxy Compounds; Glutathione; Humans; Isoenzymes; Mass Spectrometry; Methamphetamine; Microsomes, Liver; Molecular Structure; Oxidation-Reduction; Propanols; Stereoisomerism; Styrenes; Time Factors