title: The Norcoclaurine Pathway is Operative in Berberine Biosynthesis in Coptis japonica.
abstract: The commercially used cell suspension culture of COPTIS JAPONICA Makino (Ranunculaceae) incorporates [beta- (13)C]tyrosine into both halves of the berberine molecule (isoquinoline and benzyl portion) while L-[3'- (18)O]DOPA only labels the isoquinoline portion of this molecule. This labelling pattern indicates that different C (6)-C (2) units derived from tyrosine form this molecule. This result and the incorporation of ( S)-[1- (13)C] norcoclaurine into berberine demonstrates that the biosynthesis of protoberberine alkaloids in COPTIS involves the norcoclaurine but not the norlaudanosoline pathway.
authors.affiliation: Lehrstuhl für Pharmazeutische Biologie, Universität München, D(W)-8000 München 2, Federal Republic of Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Müller
authors.forename: M H
authors.initials: MH
authors.lastname: Zenk