Abstract: Using flavonoids from Hippophae rhamnoides L.berry (ZYCFJ) as reference,the antioxidant activities of flavonoids in branches and leaves of Hippophae rhamnoides L.from Zhangye (ZYCF) and Xinjiang (XJCF) were evaluated by measuring their scavenging activity against DPPH,ABTS,hydroxyl,superoxide anion radicals and reducing Fe³⁺ and inhibiting nitroso.The results showed that at 50 μg/mL concentration level,the clearance rates of ZYCFJ,ZYCF and XJCF on ABTS+ were 60.8%,42.6%,45.4%,and on DPPH were 95.7%,80.6%.88.6%.When flavonoids concentrations higher than 40 μg/mL,the scavenging activity against DPPH and ABTS+ of ZYCFJ was better than XJCF and ZYCF.At 500 μg/mL concentration level,the scavenging rates of ZYCFJ,ZYCF and XJCF on ·OH were 92.7%, 88.9%, 98.6%,and on O₂^- were 76.5%,70.6%,82.4%,and inhibition ratio of ZYCFJ,ZYCF and XJCF on nitrite were 98.7%,76.8%,83.7%.In term of the inhibition rates of nitrite and the reduction of Fe³⁺,ZYCFJ was better than that of ZYCF and XJCF.The scavenging effect of ZYCFJ,ZYCF and XJCF on superoxide anion and hydroxyl free radical were equivalent.

Key words: Hippophae rhamnoides L.branch;flavonoids, Hippophae rhamnoides L.from Zhangye, Hippophae rhamnoides L.from Xinjiang;antioxidant activity