Phenolic constituents of the inflorescences of Sorbus torminalis (L.) Crantz

摘要

Torminaloside, a new acylated flavonol glycoside (3,5,7,4'-tetrahydroxy-3'-methoxyflavone-3-O-[6 ''-O-(3'''-hydroxy-3'''-methylglutaroyl)]-beta-D-galactopyranoside, 6), together with five further methoxylated flavones 1-5, hyperoside (7), isoquercitrin (8), chlorogenic acid (9) and neochlorogenic acid (10), were isolated for the first time from Sorbus torminalis (L.) Crantz. The structures of the isolates were elucidated by extensive spectroscopic studies, including UV, IR, 1D- and 2D-NMR, LSI-MS and HR-LSI-MS experiments. In addition to torminaloside, three further flavonoids: 5,7,4'-trihydroxy-3'-methoxyflavone- 7-O-beta-D-glucopyranoside (1), 3,5,7,4'-tetrahydroxy-8,3'-dimethoxyflavone-3-O-beta-D-glucopyranoside (2), and 3,5,7,4'-tetrahydroxy-3'-methoxyflavone-3-O-beta-D-galactopyranoside (4) were found for the first time in the genus Sorbus