Contents and Antioxidant Activity of Antioxidant Substances in Various Organic Solvent Extraction Fractions from Xinjiang Medicinal Mulberry Branch Ethanolic Extract

In this study,Xinjiang medicinal mulberry( Morus nigra L.) branch ethanolic extract and its different organic solvent extraction fractions were used as test samples to detect and analyze the contents of total polyphenolics,total flavonoids and antioxidant activities using TLC-autography technology. The yield of petroleum ether extraction fraction,ethyl acetate extraction fraction,n-butanol extraction fraction,and residue water phase fraction was 2. 85%,27. 81%,36. 63%and 31. 02%,respectively. The antioxidant activities of petroleum ether and ethyl acetate extraction fractions were significantly higher than those of n-butanol extraction fraction and residue water phase fraction. The sum of mass ratios of total polyphenolics and total flavonoids in the first two extraction fractions was 211. 75 mg /g and 764. 27 mg /g. In vitro bioactivity assay displayed that the reducing power( calculated as equivalence to vitamin C) of mul- berry branch ethanolic extract,petroleum ether and ethyl acetate extraction fractions was 58. 25,15. 63 and 202. 50 mg /g respectively,and their inhibitory concentration 50%( IC50)in scavenging 1,1-diphenyl-2-picrylhydrazyl( DPPH) free radical was 0. 52,0. 32 and 0. 05 g /L respectively. The results demonstrated that Morus nigra L. branch ethanolic extract has strong antioxidant activity and the active substances mainly exist in petroleum ether and ethyl acetate extraction fractions.