Phenylacetyl-CoA 1,2-epoxidase (EC 1.14.13.149, ring 1,2-phenylacetyl-CoA epoxidase, phenylacetyl-CoA monooxygenase, PaaAC, PaaABC(D)E) is an enzyme with systematic name phenylacetyl-CoA:oxygen oxidoreductase (1,2-epoxidizing). This enzyme catalyses the following chemical reactionphenylacetyl-CoA + NADPH + H+ + O2 2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA + NADP+ + H2O