Extraction and DPPH Radical Scavenging Activity of Flavonoids from Rose Flower Buds

The purpose of this study was to optimize conditions for the extraction of flavonoids from rose flower buds and to explore the DPPH radical scavenging capacity of flavonoids from rose flower buds using vitamin C and vitamin E as controls.We established the optimal extraction conditions as follows: 60% ethanol as an extraction solvent at a solvent-tosolid ratio of 15:1(mL/g),40 ℃ and an extraction duration of 1.5 h.The extraction yield of flavonoids under the optimized conditions was 40.87% and the obtained extract revealed a DPPH radical scavenging rate of 88.28%.Its DPPH radical scavenging activity was inferior to that of VC but superior to that of VE and the IC50 values of these three antioxidants were 12.50,7.00 mg/L and 13.95 mg/L,respectively.