title: Dihydroflavonols from Lannea coromandelica.
abstract: The dihydroflavonols, (2R,3S)-(+)-3',5-dihydroxy-4',7-dimethoxydihydroflavonol and (2R,3R)-(+)-4',5,7-trimethoxydihydroflavonol were isolated from the stem bark of Lannea coromandelica, along with the known (2R,3R)-(+)-4',7-di-O-methyldihydroquercetin, (2R,3R)-(+)-4',7-di-O-methyldihydrokaempferol and (2R,3R)-(+)-4'-O-methyldihydroquercetin. All five compounds were isolated for the first time from the genus Lannea; furthermore, (2R,3S)-(+)-3',5-dihydroxy-4',7-dimethoxydihydroflavonol, was a rare cis-type isomer. The structures of all compounds were elucidated by spectroscopic methods including 2D NMR and CD analysis.
authors.affiliation: Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: M T
authors.initials: MT
authors.lastname: Islam
authors.forename: S
authors.initials: S
authors.lastname: Tahara
mesh_terms: D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D019685:Rosales / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D005419:Flavonoids