Delta12-fatty-acid desaturase (EC 126.96.36.199, Delta12 fatty acid desaturase, Delta12(omega6)-desaturase, oleoyl-CoA Delta12 desaturase, Delta12 desaturase, Delta12-desaturase) is an enzyme with systematic name acyl-CoA,hydrogen donor:oxygen Delta12-oxidoreductase. This enzyme catalyses the following chemical reaction
acyl-CoA + reduced acceptor + O2
Delta12-acyl-CoA + acceptor + 2 H2
In the yeast Lipomyces starkeyi and in the American cockroach, this microsomal enzyme converts oleoyl-CoA into linoleoyl-CoA.