Omega- and (omega-1)-hydroxylation of 1-dodecanol by frog liver microsomes

Frog liver microsomes catalyzed the hydroxylation of 1-dodecanol into the corresponding omega- and (omega-1)-hydroxy derivatives. The hydroxylation rate for 1-dodecanol was much lower than that for lauric acid. Both NADPH and O2 were required for hydroxylation activity. NADH had no effect on the hydroxylation. The hydroxylating system was inhibited 49% by CO at a CO:O2 ratio of 4.0. The formation of omega-hydroxydodecanol was more sharply inhibited by CO than was the formation of (omega-1)-hydroxydodecanol, implying that more than one cytochrome P-450 was involved in the hydroxylation of 1-dodecanol and that CO has a higher affinity for the P-450 catalyzing the omega-hydroxylation. The formation of laurate during the incubation of 1-dodecanol with frog liver microsomes suggests that a fatty alcohol oxidation system is also present in the microsomes. NAD+ was the most effective cofactor for the oxidation of 1-dodecanol and NADP+ had a little effect. Pyrazole (an inhibitor of alcohol dehydrogenase) had a slight inhibitory effect on the oxidation and sodium azide (an inhibitor of catalase) had no effect.