Reaction: (1) ipecoside + H2O = ipecoside aglycone + D-glucopyranose
(2) 6-O-methyl-N-deacetylisoipecoside + H2O = 6-O-methyl-N-deacetylisoipecoside aglycone + D-glucopyranose
Glossary: ipecoside = methyl (2S,3R,4S)-4-{[(1R)-2-acetyl-6,7-dihydroxy-1,2,3,4-tetrahydro-1-isoquinolinyl]methyl}-2-(β-D-glucopyranosyloxy)-3-vinyl-3,4-dihydro-2H-pyran-5-carboxylate
Other name(s): 6-O-methyl-deacetylisoipecoside β-glucosidase; IpeGlu1
Systematic name: ipecoside glucohydrolase
Comments: 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 1α(S)-N-deacetylisoipecoside and 1β(R)-N-deacetylipecoside epimers as substrate, with preference for the 1β(R)-epimer. 6-O-methyl-N-deacetylisoipecoside is an intermediate in the biosynthesis of the medicinal alkaloid emetine.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Nomura, T., Quesada, A.L. and Kutchan, T.M. The new β-D-glucosidase in terpenoid-isoquinoline alkaloid biosynthesis in Psychotria ipecacuanha. J. Biol. Chem. 283 (2008) 34650-34659. [PMID: 18927081]