A gallic acid derivative and polysaccharides with antioxidative activity from rose (Rosa rugosa) flowers

In this study, the major antioxidant components of rose flower were identified. An aqueous extract of rose flowers was chromatographed on CM-cellulose in ammonium acetate buffer (10 mM, pH 4.5) to yield three un-adsorbed peaks F1, F2 and F3. Each of these peaks was subjected to gel filtration on Sephadex G75. F1 yielded two peaks, whereas both F2 and F3 gave rise to only a single peak. Spectroscopic studies using NMR and FTIR revealed that F3 is a gallic acid derivative. It exhibited the highest antioxidative potency. F1-a derived from F1 by gel filtration is mainly a polysaccharide-peptide complex with less potent antioxidative activity. F2 is a polysaccharide also with reduced antioxidant activity. This study demonstrates, for the first time, the presence of both gallic acid derivatives and polysaccharides as major antioxidant principles of the aqueous extract of rose flowers.