American Journal of Biochemistry and Biotechnology

Response Surface Optimized Ultrasonic Assisted Extraction of Total Flavonoids from Walnut Leaves and In Vitro Antibacterial Activities

Jingjing Fu, Haifang Xiao, Shaoxuan Yu, Han Wu, Aydin Berenjian and Yuanda Song

DOI : 10.3844/ajbbsp.2017.176.188

American Journal of Biochemistry and Biotechnology

Volume 13, Issue 4

Pages 176-188


In this paper, the optimum extraction conditions of total flavonoids extracted from walnut leaves subjected to Ultrasonic Assisted Extraction (UAE) were optimized by Response Surface Methodology (RSM). The mathematical model showed the high coefficient of measurement (R2 = 0.9938) which indicated that this model could be used to guide the response surface methodology. The optimum extraction parameters for extracting flavonoids from walnut leaves determined in this study were extraction temperature 47.73°C, extraction time 30.79 min, ethanol concentration 72.89% (v/v). Under the optimal extraction conditions, the flavonoids yield was about 3.5315%. Statistical analysis of the results showed that extraction temperature, extraction time and ethanol concentration significantly affected the extraction yield of total flavonoids. In addition, the antibacterial activity assays of the flavonoids were carried out and it was demonstrated that the total flavonoids extracted at the optimum conditions had pronounced antibacterial effects against the four bacterial species. Therefore, this study suggested that walnut leaves are promising resources with antibacterial properties for the development of phytomedicines.


© 2017 Jingjing Fu, Haifang Xiao, Shaoxuan Yu, Han Wu, Aydin Berenjian and Yuanda Song. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.