ID 1.14.16.6 DE mandelate 4-monooxygenase. AN L-mandelate 4-hydroxylase. AN mandelic acid 4-hydroxylase. CA (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + (S)-mandelate + O2 = (6R)-L- CA erythro-6,7-dihydrobiopterin + (S)-4-hydroxymandelate + H2O. //