The metabolism of nonradiolabeled, stereoisomeric mixtures of 3-acetyl-2-(2,6-dimethyl-5-heptenyl)oxazolidine (I), a new citronelial-based insect repellent, by induced and uninduced rat liver microsomes has been examined in a NADPH-generating system at a substrate concentration of 1.67 mM. By comparison of retention times and mass spectra of the metabolites with the products from oxidation of I with selenium dioxide, the allylic methyl carbons of the isobutenyl group were identified as the major sites of oxidative metabolism, with two samples of I prepared from different sources of (+/-)-citronelial. Both diastereomeric and E-Z isomeric forms of the metabolites were separated by high resolution capillary gas chromatography with Carbowax 20M-terephthalic acid. Diastereomeric mixtures of unmetabolized I, E alcohol (II), Z alcohol (III), and E aldehyde (IV) were detected in postsincubate extracts. From integration of peak areas, the mean ratio of II to III was 70:30 in 47 extracts.
Alcohols Animals