A cytochrome P450 monooxygenase that may play a major role in the metabolism of arachidonic acid in the intestinal tract (PubMed:10908295, PubMed:9721182). Exhibits regioselective hydroxylase and epoxidase activity toward arachidonic acid, producing 16(R)-hydroxyeicosatetraenoic acid (HETE) and (14R,15S)-epoxyeicosatrienoic acid (EpETrE) as major products (PubMed:10908295). 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 (CPR; NADPH-ferrihemoprotein reductase) (PubMed:10908295). (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 16(R)-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 16(S)-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (14R,15S)-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (14S,15R)-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Lipid metabolism; arachidonate metabolism. Liver, brain, kidney, and intestine, with trace amounts in lung and heart (PubMed:9721182, PubMed:10908295). Expressed throughout the intestinal tract, with higher expression levels in jejunum, cecum and colon (PubMed:10908295). Belongs to the cytochrome P450 family.