Microwave-assisted extraction and antioxidant activity of flavonoids from rose

The microwave-assisted extraction of flavonoids from rose and its oxidation resistance were investigated. The results showed that the optimal temperature,ratio of liquid to solid,alcohol concentration,microwave extraction time and microwave power were 65℃,1∶55,65%,45min and 700W,respectively,and the extraction ratio for flavonoids was 82.29%.The obtained total flavonoids content was 2.2%. The antioxidant study showed that extraction of acetic ether,n-butanol and water of the flavonoids had activity of scavenging DPPH·,whose IC50 value were 6.52,9.04,6.87μg/mL,respectively. The inhibitory rate to O-2· of extraction of acetic ether,n-butanol and water whose concentration were 100μg/mL were 14.43%,27.83% and 23.21%,respectively. The inhibitory rate to ·OH of extraction of acetic ether,n-butanol and water whose concentration are 500μg/mL were 23.74%、43.51%、32.75%.