Hepatic microsomal oxygenation of aldehydes to carboxylic acids

Hepatic microsomal oxygenation of aldehydes to carboxylic acids was investigated. Aldehydes (veratrum aldehyde, cinnamic aldehyde, myrtenal, cuminaldehyde, 3-phenylpropionaldehyde, perillaldehyde and 9-anthraldehyde) were incubated with hepatic microsomes of mice in the presence of an NADPH-generating system under 18O2 (97 atom%). The incorporation of oxygen-18 into carboxylic acids formed was determined by gas chromatography-mass spectrometry. Oxygen-18 was incorporated into the carboxylic acids formed from all aldehyde substrates examined. Hepatic microsomal formation of 3,4-dimethoxybenzoic acid and cumic acid from veratrum aldehyde and cuminaldehyde, respectively, was inhibited by CO and SKF 525-A. These results indicate that the oxygenation of aldehydes which may be catalyzed by cytochrome P450 is a common reaction in the biotransformation of xenobiotic aldehydes.