title: Antioxidant activity and proanthocyanidin profile of Selliguea feei rhizomes.
abstract: Proanthocyanidins from the rhizomes of Selliguea feei (PSFs) were solvent-extracted and fractionated by Sephadex LH-20 column chromatography to give a 2.42% isolated yield (dry matter basis). 1H-NMR spectroscopy revealed the mean degree of polymerization (mDP) to be 2.6. 13C-NMR analysis showed typical signals for afzelechin/epiafzelechin units. Clear peaks at 76 ppm and 84 ppm indicated that both stereoisomers (afzelechin/epiafzelechin) are present. In agreement with the NMR spectra, the ESI-MS spectrum indicated that PSFs are mainly monomers to trimers consisting of afzelechin/epiafzelechin units with A-type and B-type interflavanyl linkages. A trimer was purified and identified as demethylated selligueain B. Thiolysis confirmed the structure and the thiolytic products, methyl 2-[(2R, 3R, 4S)-3,5,7-trihydroxy-2-(4-hydroxyphenyl)chroman-4-yl]acetate (1) and 4β-(carboxymethyl)sulphanylepiafzelechin-(2β→O→7,4β→8)-epiafzelechin methyl ester (2), were purified and characterized. Selligueain A, demethylated selligueain B, compounds 1 and 2 possess high antioxidant capacity at 1.18 × 104, 1.16 × 104, 0.95 × 104 and 1.29 × 104 µmol TE/g, respectively.
authors.affiliation: College of Bioscience & Biotechnology, Fuzhou University, Fuzhou 350108, Fujian, China.
authors.forename: Caili
authors.initials: C
authors.lastname: Fu
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
authors.forename: Wei Ling
authors.initials: WL
authors.lastname: Ng
authors.forename: Lixia
authors.initials: L
authors.lastname: Song
authors.forename: Dejian
authors.initials: D
authors.lastname: Huang
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry; D003911:Dextrans / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010636:Phenols / Q000737:chemistry; D029621:Polypodiaceae / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry*; D027343:Rhizome / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D003911:Dextrans; D005419:Flavonoids; D010636:Phenols; D044945:Proanthocyanidins; C120647:epiafzelechin; C084699:selligueain A; D002392:Catechin; C025614:sephadex; C510796:afzelechin