Study on the polyphenolic contents and antioxidant activities of extracts from Hesperethusa crenulata bark

The antioxidant activities of Hesperethusa crenulata bark extracts from methanol,ethanol,ethyl acetate and aqueous were investigated in this assay. The total polyphenolic contents of the extracts were evaluated,using the Folin-Ciocalteu method. The polyphenolic contents of methanol and ethanol extracts were higher compared to ethyl acetate and aqueous extracts,which were 58. 59、 50. 47mg·g-1,respectively. The antioxidant and free radical scavenging activities of extracts of the plant were also assessed against 2,2-diphenyl-1-picrylhydrazyl( DPPH),10-phenanthroline-Fe2+oxidative assay of hydroxyl radical scavenging activity,hydrogen peroxide-scavenging activity,reducing power and phosphomolybdenum method. The results indicated that the scavenging abilities of ethanol extract on DPPH,·OH、H2O2were above 90% at the concentration of 1. 0mg·mL-1. The IC50of the ethanol extract on DPPH,·OH,H2O2scavenging activities were 234. 2、555. 2、60. 1μg·mL-1.