title: Guanidine alkaloids and Pictet-Spengler adducts from black cohosh (Cimicifuga racemosa).
abstract: As an extension of work on the recently discovered nitrogenous metabolites from Cimicifuga/Actaea species, three new guanidine alkaloids have been isolated and characterized from C. racemosa (syn. A. racemosa) roots. Of these, cyclo-cimipronidine (1) and cimipronidine methyl ester (2) are congeners of cimipronidine (3), whereas dopargine (5) is a derivative of dopamine. By employing NMR- and MS-guided chemodiversity profiling of a polar serotonergic (5-HT(7)) fraction, the guanidine alkaloids were initially detected in a clinical extract of black cohosh and were isolated along with a congener of salsolinol 4, 5, and 3-hydroxytyrosol 3-O-glucoside (7). The structures of 1, 2, and 5 were confirmed by 1D and 2D NMR spectroscopy as well as LC-MS and HRMS spectroscopy. A plausible biosynthetic relationship may be inferred between the homoproline-analogue cimipronidines and the dopamine-derived Cimicifuga alkaloids. These strongly basic and frequently zwitterionic nitrogenous metabolites contribute considerable chemical diversity to the polar serotonergic fraction of black cohosh.
authors.affiliation: UIC/NIH Center for Botanical Dietary Supplements Research and Program for Collaborative Research in the Pharmaceutical Sciences, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612.
authors.forename: Tanja
authors.initials: T
authors.lastname: Gödecke
authors.forename: David C
authors.initials: DC
authors.lastname: Lankin
authors.forename: Dejan
authors.initials: D
authors.lastname: Nikolic
authors.forename: Shao-Nong
authors.initials: SN
authors.lastname: Chen
authors.forename: Richard B
authors.initials: RB
authors.lastname: van Breemen
authors.forename: Norman R
authors.initials: NR
authors.lastname: Farnsworth
authors.forename: Guido F
authors.initials: GF
authors.lastname: Pauli
mesh_terms: D000470:Alkaloids / Q000737:chemistry* / Q000302:isolation & purification*; D031885:Cimicifuga / Q000737:chemistry*; D006146:Guanidines / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D009515:New Jersey; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D006146:Guanidines; D011759:Pyrrolidines; C504638:cimipronidine