Catalyzes the condensation of tyramine and 3,4-dihydroxybenzaldehyde (3,4-DHBA) to form norbelladine, the common precursor to all Amaryllidaceae alkaloids such as galanthamine, lycorine and haemanthamine, and including haemanthamine- and crinamine-type alkaloids, promising anticancer agents. 3,4-dihydroxybenzaldehyde + AH2 + tyramine = A + H2O + norbelladine Optimum pH is 4. Alkaloid biosynthesis. Mostly expressed in bulbs, and, to a lower extent, in roots, stems, leaves and flowers. Belongs to the BetVI family.