Enzymatic reactions [BR:br08201]
1. Oxidoreductase reactions
1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen
1.14.19 With oxidation of a pair of donors resulting in the reduction of O2 to two molecules of water
1.14.19.41
R07489 beta-Sitosterol + NADPH + H+ + Oxygen <=> Stigmasterol + NADP+ + 2 H2O