title: Condensed tannins from mangrove species Kandelia candel and Rhizophora mangle and their antioxidant activity.
abstract: The structures of condensed tannins isolated from two mangrove species, Kandelia candel and Rhizophora mangle, were characterized by 13C nuclear magnetic resonance (NMR) spectroscopy and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. Results demonstrate that large heterogeneity occurs in degree of polymerization, pattern of hydroxylation, and substitution with monosaccharides in the structures of the condensed tannins. Condensed tannin oligomers from K. candel and R. mangle were shown to be heterogeneous mixtures consisting of procyanidin and prodelphinidin structural units with the former dominating. The MALDI-TOF mass spectra contained masses corresponding to a distinct oligomeric series of glycosylated heteropoly flavan units. In addition, condensed tannins from two mangrove plants were screened for their potential antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) model systems.
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Zhang
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Lin
authors.forename: Hai-Chao
authors.initials: HC
authors.lastname: Zhou
authors.forename: Shu-Dong
authors.initials: SD
authors.lastname: Wei
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000737:chemistry; D010851:Picrates / Q000378:metabolism; D044945:Proanthocyanidins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D043982:Rhizophoraceae / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D044945:Proanthocyanidins; C004931:1,1-diphenyl-2-picrylhydrazyl