Catalytic Reactions of Activation Enzymes

Phase I activation enzymes catalyze oxidation, reduction, and hydrolysis reactions, resulting in the introduction of functional groups to lipophilic foreign compounds and the increase in the water solubility of the parent compounds. The functional groups are introduced by the reactions, such as N-oxidation, S-oxidation, hydroxylation, O- and N-dealkylation, hydrolysis, and epoxidation, where oxidases, reductases, and hydrolases are involved in oxidation, reduction, and hydrolysis reactions.