Background：

A cytochrome P450 monooxygenase involved in the metabolism of steroid hormones and vitamins during embryogenesis. Mechanistically， uses molecular oxygen inserting one oxygen atom into a substrate， and reducing the second into a water molecule， with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes 3beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone， DHEA)， a precursor in the biosynthesis of androgen and estrogen steroid hormones. Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1)， particularly D-ring hydroxylated estrone at the C16-alpha position. Mainly hydroxylates all trans-retinoic acid (atRA) to 4-hydroxyretinoate and may play a role in atRA clearance during fetal development. Also involved in the oxidative metabolism of xenobiotics including anticonvulsants.