Abstract: In the present study,the main components of rape bee pollen supercritical fluid extract (PSFE) were qualitatively and quantitatively analyzed by HPLC with fluorescence detector (FLD) using pre-column fluorescence derivatization.In addition,superoxide anion free radical (O₂^-·),DPPH free radical (DPPH·) and hydroxyl free radical (·OH) assays were used to evaluate the free radicals scavenging activities of PSFE.The results indicated that PSFE contained abundant free fatty acid (FFA),in which the saturated FFA accounted for 58% of the total FFA and the unsaturated FFA accounted for 42%.The unsaturated FFA C18:3 was determined to have the highest concentration (10933.69 μg/g).Moreover,PSFE showed various degrees of ability to scavenge these three typical free radicals.The scavenging effects of PSFE on DPPH· were much higher than the positive control L-ascorbic acid.As the concentration increased,the scavenging rate was getting more significant,even reach to 60.29%.Nevertheless,the scavenging rates of PSFE on O₂^-· and ·OH were both less significant than the positive control and were 11.99% and 7.59%,respectively,in the range of experimental concentrations.

Key words: rape bee pollen supercritical fluid extract, pre-column fluorescence derivatization, HPLC-FLD, superoxide anion free radical, DPPH free radical, hydroxyl free radical