Hydroxylation of Aliphatic Compounds by Liver Microsomes

Abstract

Aliphatic compounds are hydroxylated to the corresponding isomeric alcohols by an unspecific hydroxylation system in the endoplasmic reticulum of the liver cell. As models for this reaction the following hydroxylation systems were investigated: 1. trifluoroperacetic acid, 2. the photolysis of 2,2-dimethylquinoxaline-di-N-oxide and 3. the system Fe2⊖/2-mercaptobenzoic acid/O2. 2-Methylbutane, methylcyclohexane and n-pentane are hydroxylated by a selective mechanism probably involving an oxenoid species. The pattern of isomeric alcohols closely resembles that obtained of rat liver microsomes indicating a hydroxylation mechanism of similar selectivity. From comparison with the nonenzymatic systems it is possible to conclude on minor steric effects in the microsomal hydroxylation of these alkanes.