The enzyme, isolated from the roots of the plant Carapichea ipecacuanha, preferentially hydrolyses glucosidic ipecoside alkaloids except for their lactams, but shows poor or no activity toward other substrates. IpeGlu1 activity is extremely poor toward 7-O-methyl and 6,7-O,O-dimethyl derivatives. However, 6-O-methyl derivatives are hydrolysed as efficiently as non-methylated substrates. IpeGlu1 accepts both 1alpha(S)-N-deacetylisoipecoside and 1beta(R)-N-deacetylipecoside epimers as substrate, with preference for the 1beta(R)-epimer. 6-O-methyl-N-deacetylisoipecoside is an intermediate in the biosynthesis of the medicinal alkaloid emetine.