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Polyphenols from Polygala spp. and Their Antioxidant Activity
Author(s) -
Cervellati Rinaldo,
Innocenti Gabbriella,
Dall'Acqua Stefano,
Costa Stefano,
Sartini Elena
Publication year - 2004
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.200490035
Subject(s) - chemistry , antioxidant , polyphenol , resorcinol , biphenyl , phenols , phenol , flavonoid , stereochemistry , organic chemistry
Members of Polygalaceae are known to contain a variety of different polyphenolic compounds such as xanthones, flavonoids, and biphenyl derivatives. Here, we report the isolation and structural characterization of two new phenol derivatives, named alpestrin (=3,3′,5′‐trimethoxy[1,1′‐biphenyl]‐4‐ol; 10 ) and alpestriose A (=6‐ O ‐benzoyl‐1‐ O ‐{6‐ O ‐acetyl‐3‐ O ‐[(4‐hydroxy‐3,5‐dimethoxyphenyl)prop‐2‐enoyl]‐ β ‐ D ‐fructofuranosyl}‐ α ‐ D ‐glucopyranoside; 11 ), and of four known compounds ( 12 – 15 ) from the MeOH extract of Polygala alpestris. The relative in vitro antioxidant activities of these compounds, in comparison with other phenolic substances from Polygala vulgaris , were evaluated by means of the Briggs Rauscher ( BR ) oscillating reaction, a method based on the inhibitory effects of antioxidant free‐radical scavengers. The experimental antioxidant‐activity values (relative to resorcinol as a standard) were compared with those calculated on the basis of the bond‐dissociation enthalpies. The structure/activity relationships for the compounds examined are also discussed.