title: HPLC, NMR and MALDI-TOF MS analysis of condensed tannins from Lithocarpus glaber leaves with potent free radical scavenging activity.
abstract: Using acid-catalyzed degradation in the presence of cysteamine, the condensed tannins from Lithocarpus glaber leaves were characterized, following thiolysis, by means of reversed-phase HPLC, 13C-NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analyses. The thiolysis reaction products showed the presence of the procyanidin (PC) and prodelphinidin (PD) structures. The 13C-NMR spectrum revealed that the condensed tannins were comprised of PD (72.4%) and PC (27.6%), and with a greater content of cis configuration rather than the trans configuration of C2-C3. The MALDI-TOF MS analysis proved the presence of PD units, and the maximum degree of polymerization (DP) was an undecamer. The antioxidant activity of condensed tannins from L. glaber leaves was evaluated by using a free radical scavenging activity assay.
authors.affiliation: Key Lab of Ministry of Education for Coast and Wetland Ecosystems, Xiamen 361005, P.R. China. zhll20086@gmail.com
authors.forename: Liang Liang
authors.initials: LL
authors.lastname: Zhang
authors.forename: Yi Ming
authors.initials: YM
authors.lastname: Lin
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D029962:Fagaceae / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000032:analysis* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013634:Tannins / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D016166:Free Radical Scavengers; D013634:Tannins