Component of the seco-iridoid and derivatives monoterpenoid indole alkaloids (MIAs, e.g. vinblastine, catharanthine, tabersonine, vincadifformine, vindoline, vincristine, quinine and strychnine) biosynthesis pathway. Converts precondylocarpine acetate to dihydroprecondylocarpine acetate. dihydroprecondylocarpine acetate + NADP(+) = H(+) + NADPH + precondylocarpine acetate Binds 2 Zn(2+) ions per subunit. Alkaloid biosynthesis. Homodimer. Interaction with catharanthine synthase (CS) and tabersonine synthase (TS). Strong accumulation of precondylocarpine acetate. Belongs to the zinc-containing alcohol dehydrogenase family.