Deacetylates 17-O-acetylajmaline and 17-O-acetylnorajmaline, but is inactive toward other acetylated alkaloids. 17-O-acetylajmaline + H2O = acetate + ajmaline + H(+) 17-O-acetylnorajmaline + H2O = acetate + H(+) + norajmaline Optimum pH is 8.0. Half maximum activity is seen at pH 6.5 and 9.8. Optimum temperature is 53 degrees Celsius. Belongs to the 'GDSL' lipolytic enzyme family.