ω-Oxidation of Branched-Chain Fatty Acids in Rat Liver Homogenates

Abstract

The synthesis of tritium-labeled 14-methylpentadecanoic acid, 15-methylhexadecanoic acid and 16-methylheptadecanoic acid is described. These acids were found to be oxidized into a number of water-soluble and ether-soluble products by the 800×g supernatant fluid of rat liver homogenate. In the presence of mitochondrial or microsomal fraction fortified with NADPH, the iso-fatty acids were converted mainly into ω-oxidized products. Addition of boiled 100 000×g supernatant fluid or NAD increased the yield of ω-oxidized products. Gas-chromatographic and mass-spectrometric analyses of the products formed showed that the main metabolites were the ω-hydroxy iso-fatty acid and the corresponding dicarboxylic acid.