Comparison of the antioxidant properties of various solvent extracts from Dipsacus asperoides and identification of phenolic compounds by LC-ESI-QTOF-MS-MS

In this study, Dipsacus asperoides was separately extracted in three solvents (water, methanol and acetone), and the antioxidant activities of each extract were investigated through assays of DPPH, ABTS, β-carotene/linoleic acid system and reducing power. The total phenolic acids, flavonoids and saponins in each solvent extract were calculated for a correlation analysis. The phenolic compounds in the extracts were identified by LC-ESI-QTOF-MS-MS. The results showed that the three extracts exhibited antioxidant effects in a concentration-dependent manner, and the water extracts exerted the highest antioxidant activity effect followed by the methanol and acetone extracts. The correlation analysis indicated that the total phenolic components presented the greatest contribution to the antioxidant activities. Fifteen main phenolic compounds were identified in the water extracts, and three of these compounds had not been previously identified in D. asperoides. The results suggest that water extraction of D. asperoides is a promising source of natural antioxidants.