Abstract: The aim of this work was to determine the total contents of phenols,flavonoids and Vc in the fruits of 5 selected Hippophae rhamnoides L. cultivars from Hexi corridor and to evaluate the scavenging activity of H. rhamnoides fruits methanol extracts on reactive oxygen species (ROS),namely hydroxyl radical (·OH),nitric oxide (NO·),superoxide anion (O₂^-·). Altogether,5 cultivars of this fruit species presented total phenolic contents ranging from 8.25-13.26 g of gallic acid/kg fresh weight,Vc contents ranging from 1.843.46 g/kg fresh weight,flavonoids contents ranging from 3.68-5.25 g rutin/kg fresh weight,and high contents of phenols,flavonoids and Vc were obtained from H. neurocarpa S.W. and H. thibetana Schlecht fruits. The crude methanol extracts from H. neurocarpa and H. thibetana fruits showed high inhibitory effects on reactive ROS. There were high correlations between the flavonoids contents and the ROS scavenging effects. The obtained results would contribute to the popularization of H. rhamnoides as a promising source for the food industry.

Key words: Hippophae rhamnoides L., flavonoids, phenolics, Vc, radical scavenging