title: Activity-guided isolation and identification of radical scavenging components in Gao-Cha tea.
abstract: Gao-Cha is a traditional Chinese health tea made from Acer ginnala. We performed a components and radical scavenging activity analysis to identify any medicinal components in this tea. High performance thin layer chromatography (HPTLC)-1,1-Diphenyl-2-picryhydrazyl (HPTLC-DPPH) assay showed that the methanolic extract contained strong radical scavengers. Quantitative analysis revealed that the IC(50) of the extract against 1 mM DPPH was 52.7 ± 0.6 μg/mL. Bioactive-guided isolations led to procurement of 3 radical scavengers with IC(50)s of 17.5 ± 2.1, 29.3 ± 2.5, and 21.6 ± 1.7 μg/mL, respectively. Analysis of the high resolution-electric spray ionization-mass spectrometer and (1)H, (13)C, distortionless enhancement by polarization transfer at 135°, heteronuclear quantum coherence, correlating spectroscopy coupling, and heteronuclear multiple bond coherence (HMBC) data revealed that the compounds were methyl 3, 4, 5-trihydroxybenzoate (1), quercetin-3-O-α-rhamnopyranoside (2), and 2,6-bis (3,4,5-trihydroxybenzoyl)-aceritol (3). Bioactive combined components analysis revealed that, apart from compounds 1, 2, and 3, the tea possibly contained radical scavengers: ginnalin A (4) and B (5), 2″-O-Galloylquercitrin (6) and 3″-O-Galloyl-quercitrin (7). Compounds 2, 6, and 7 were isolated from Acer ginnala for the first time. The positions of the 2 galloyl moieties in compound 3 were unambiguously established by the HMBC spectrum for the first time.
authors.affiliation: Anhui Agricultural Univ., Hefei 230036, China.
authors.forename: Rui-Li
authors.initials: RL
authors.lastname: Lu
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Hu
authors.forename: Tao
authors.initials: T
authors.lastname: Xia
mesh_terms: D031002:Acer / Q000737:chemistry*; D001628:Beverages / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006027:Glycosides; D015394:Molecular Structure; D009005:Monosaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D018520:Plant Shoots / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: C560408:2,6-bis(3,4,5-trihydroxybenzoyl)aceritol; D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D005960:Glucosides; D006027:Glycosides; D009005:Monosaccharides; D010936:Plant Extracts; C509385:quercetin-3-O-alpha-L-rhamnopyranoside; C052082:methyl gallate; D005707:Gallic Acid; D011794:Quercetin