title: Acetylation serves as a protective group in noscapine biosynthesis in opium poppy.
abstract: We have characterized four sequential enzymes that transform 1-hydroxy-N-methylcanadine to narcotoline hemiacetal, completing our elucidation of noscapine biosynthesis in opium poppy. Two cytochromes P450 catalyze hydroxylations at C13 and C8 on the protoberberine scaffold, the latter step inducing ring opening and the formation of an aldehyde moiety. Acetylation at C13 before C8 hydroxylation introduces a protective group subsequently hydrolyzed by a carboxylesterase, which triggers rearrangement to a cyclic hemiacetal.
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Thu-Thuy T
authors.identifier: 0000000264593664
authors.initials: TT
authors.lastname: Dang
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Xue
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Peter J
authors.identifier: 000000027693290X
authors.initials: PJ
authors.lastname: Facchini
mesh_terms: D000107:Acetylation; D001599:Berberine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D053898:Biosynthetic Pathways; D003500:Cyclization; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D006900:Hydroxylation; D009665:Noscapine / Q000737:chemistry / Q000378:metabolism*; D010207:Papaver / Q000201:enzymology* / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D001599:Berberine; D009665:Noscapine; C004645:canadine