This plant enzyme is responsible for the last stages in the biosynthesis of the indole alkaloid ajmaline. The enzyme is highly specific for the substrates 17-O-acetylajmaline and 17-O-acetylnorajmaline as the structurally related acetylated alkaloids vinorine, vomilenine, 1,2-dihydrovomilenine and 1,2-dihydroraucaffricine cannot act as substrates [2]. This is a novel member of the GDSL family of serine esterases/lipases.