title: Two new flavonol glycosides from Dimocarpus longan leaves.
abstract: From the extracts of Dimocarpus longan Lour leaves, 2 unusual flavonol glycosides, quercetin 3-O-(3″-O-2‴-methyl-2‴-hydroxylethyl)-β-D-xyloside (1) and quercetin 3-O-(3″-O-2‴-methyl-2‴-hydroxylethyl)-α-L-rhamnopyranoside (2), as well as 10 known compounds including 2 flavonol glycosides, afzelin (3) and kaempferol-3-O-α-L-rhamnopyranoside (4), 2 flavans, (-)-epicatechin (5) and proanthocyanidin A-2 (6), 3 triterpenoids, friedelin (7), epifriedelanol (8) and β-amyrin (9), a peptide, N-benzoylphenylalanyl-N-benzoylphenylalaninate (10), and 2 sterols, β-sitosterol (11) and daucosterol (12) were isolated and identified by using combination of mass spectrometry and various 1D and 2D NMR techniques. This is the first report of flavonoid glycosides possessing a 2-methyl-2-hydroxylethoxyl group in sugar moiety from D. longan.
authors.affiliation: a School of Chemistry and Chemical Engineering, Yunnan Normal University , Kunming 650500 , P.R. China.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Xue
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wang
authors.forename: Yujiao
authors.initials: Y
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhan
authors.forename: Yegao
authors.initials: Y
authors.lastname: Chen
mesh_terms: D044948:Flavonols / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry / Q000302:isolation & purification; D029631:Sapindaceae / Q000737:chemistry*
chemical_list: D044948:Flavonols; D006027:Glycosides; D011794:Quercetin
keywords: Dimocarpus longan; Sapindaceae; flavonol glycoside