A polysaccharopeptide complex and a condensed tannin with antioxidant activity from dried rose (Rosa rugosa) flowers

In this study, the fraction (P) from an aqueous extract of dried rose (Rosa rugosa) flowers was obtained by ethanol precipitation. P was chromatographed on DEAE-cellulose. The components retained on DEAE-cellulose were eluted with a linear gradient of 0-2 M NaCl solution. Two fractions, eluted at concentrations of 0.5 M NaCl and 1 M NaCl, respectively, were obtained. These two components were designated as P1 and P2, respectively. P1 was further purified using gel filtration on Sephadex G-200. P(1) yielded two peaks, and the two components were designated as P(1-a) and P(1-b), respectively. P(1-a) was a polysaccharide-peptide complex, and P(1-b) exhibited chemical properties of a condensed tannin as revealed by FTIR and NMR assay of carbohydrate and protein contents and HPLC-ESI-MS. The molecular masses of P(1-a) and P(1-b) were 150 kDa and 8 kDa, respectively. Both P(1-a) and P(1-b) possessed antioxidant activity, with the activity of P(1-b) higher than that of P(1-a). This study demonstrated that different components from rose flowers exhibited antioxidant activity.