title: Pyridocoumarin, aristolactam and aporphine alkaloids from the Australian rainforest plant Goniothalamus australis.
abstract: Chemical investigation of the CH(2)Cl(2)/CH(3)OH extracts from aerial parts of the Australian plant Goniothalamus australis has resulted in the isolation of two pyridocoumarin alkaloids, goniothalines A (1) and B (2) as well as eight known natural products, aristolactam AII (3), enterocarpam II (4), caldensine (5), sauristolactam (6), (-)-anonaine (7), asimilobine (8), altholactone (9) and (+)-goniofufurone (10). The chemical structures of all compounds were determined by extensive spectroscopic and spectrometric analysis. Methylation of 2 using TMS-diazomethane afforded 1, which unequivocally established that both 1 and 2 possessed a 10-methyl-2H-pyrano[2,3-f]quinolin-2-one skeleton. These pyridocoumarin alkaloids are putatively proposed to arise biosynthetically from an aporphinoid precursor. Compounds 1-10 were evaluated for in vitro antimalarial activity against a chloroquine-sensitive Plasmodium falciparum line (3D7). Sauristolactam (6) and (-)-anonaine (7) exhibited the most potent antiparasitic activity with IC(50) values of 9 and 7 μM, respectively.
authors.affiliation: Eskitis Institute, Griffith University, Brisbane, Qld 4111, Australia.
authors.forename: Claire
authors.initials: C
authors.lastname: Levrier
authors.forename: Mélodie
authors.initials: M
authors.lastname: Balastrier
authors.forename: Karren D
authors.initials: KD
authors.lastname: Beattie
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Carroll
authors.forename: Frédéric
authors.initials: F
authors.lastname: Martin
authors.forename: Vanida
authors.initials: V
authors.lastname: Choomuenwai
authors.forename: Rohan A
authors.initials: RA
authors.lastname: Davis
mesh_terms: D001060:Aporphines / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry*; D054335:Goniothalamus / Q000737:chemistry*; D026121:Indole Alkaloids / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D001060:Aporphines; D003374:Coumarins; D026121:Indole Alkaloids; C081279:aporphine; C030123:coumarin