1.14.14.104 metabolism in plant-derived ajmalan alkaloid pathways, the biosynthetic intermediate vomilenine can be transformed into the anti-arrhythmic compound ajmaline, or alternatively, can isomerize to form perakine, an alkaloid with a structurally distinct scaffold. Enzyme vinorine hydroxylase, a cytochrome P450 enzyme, hydroxylates vinorine to form vomilenine, which exists as a mixture of rapidly interconverting epimers (with 21-epi-vomilenine). The cytochrome P450 also catalyzes the non-oxidative isomerization of the ajmaline precursor vomilenine to perakine. Alkaloid network in Rauwolfia serpentina from strictosidine, overview 744036 1.14.14.104 additional information proposed reaction mechanism for the isomerization of vomilenine to perakine, the introduction of a hydroxy group at C-21 allows opening of the ring via the newly formed hemiaminal. The resulting amine can then undergo a Michael addition to form perakine, overview. The conversion of vomilenine into perakine is enzymatically catalyzed by vinorine hydroxylase 744036 1.14.14.104 physiological function the unusual dual catalytic activity of vinorine hydroxylase provides a control mechanism for the bifurcation of the alkaloid pathway branches 744036