HPLC determination of phenolic compounds in different solvent extracts of mulberry leaves and antioxidant capacity of extracts
Zhenjiang Wang, Cuiming Tang, Fanwei Dai, Gengsheng Xiao, Guoqing Luo
Abstract
The antioxidant activities and phenolic contents of mulberry leave extracts obtained by aqueous mixture of acetone, ethanol and methanol were determined. Both alkaline hydrolysis and acid hydrolysis were used to extract bound phenolics. HPLC was used to determine the profile of the extracted phenolics. Three experimental assays, namely, Fe3+ reducing antioxidant power (FRAP), ABTS- and DPPH-radical scavenging activity, were employed to characterize their antioxidant activity. This indicates that acetone was the most effective solvent for extracting free phenolics from mulberry leaves, and the acetone extract exhibited the highest antioxidant capacity. In addition, alkaline hydrolysis was found to be the most efficient method for extracting bound phenolics and produced an extract with better antioxidant properties compared to acid hydrolysis.