title: Prenylated chalcones, flavone and other constituents of the twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis.
abstract: The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,5'-di-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-3'-(2-hydroxy-3-methylbut-3-enyl)-2',4'-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)-5'-(3,3-dimethylallyl)-4,2',4'-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 3'-(2-hydroxy -3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. beta-Sitosterol and its beta-d-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC.
authors.affiliation: Department of Organic Chemistry, Faculty of Science, University of Yaoundé 1, BP 812, Yaoundé, Cameroon. bngadjui@uyc.uninet.cm
authors.forename: Bonaventure T
authors.initials: BT
authors.lastname: Ngadjui
authors.forename: Jean
authors.initials: J
authors.lastname: Watchueng
authors.forename: Felix
authors.initials: F
authors.lastname: Keumedjio
authors.forename: Bathélémy
authors.initials: B
authors.lastname: Ngameni
authors.forename: Ingrid K
authors.initials: IK
authors.lastname: Simo
authors.forename: Berhanu M
authors.initials: BM
authors.lastname: Abegaz
mesh_terms: D047188:Chalcones / Q000737:chemistry / Q000302:isolation & purification*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D029586:Moraceae / Q000737:chemistry*
chemical_list: D047188:Chalcones; D047309:Flavones