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The Scientific World Journal
Volume 2014, Article ID 506971, 12 pages
http://dx.doi.org/10.1155/2014/506971
Research Article

Microwave-Assisted Simultaneous Extraction of Luteolin and Apigenin from Tree Peony Pod and Evaluation of Its Antioxidant Activity

1Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Box 332, Hexing Road 26, Harbin, Heilongjiang 150040, China
2State Engineering Laboratory for Bioresource Eco-Utilization, Northeast Forestry University, Harbin 150040, China

Received 28 April 2014; Accepted 29 August 2014; Published 22 October 2014

Academic Editor: Fred Stevens

Copyright © 2014 Hongzheng Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An efficient microwave-assisted extraction (MAE) technique was employed in simultaneous extraction of luteolin and apigenin from tree peony pod. The MAE procedure was optimized using response surface methodology (RSM) and compared with other conventional extraction techniques of macerate extraction (ME) and heat reflux extraction (HRE). The optimal conditions of MAE were as follows: employing 70% ethanol volume fraction as solvent, soaking time of 4 h, liquid-solid ratio of 10 (mL/g), microwave irradiation power of 265 W, microwave irradiation time of 9.6 min, and 3 extraction cycles. Under the optimal conditions, 151 μg/g luteolin and 104 μg/g apigenin were extracted from the tree peony pod. Compared with ME and HRE, MAE gave the highest extraction efficiency. The antioxidant activities of the extracts obtained by MAE, ME, and HRE were evaluated using a 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) free radical-scavenging assay, a ferric reducing antioxidant power assay (FRAP), and a reducing power assay. Meanwhile, the structural changes of the unprocessed and processed tree peony pod samples were analyzed by scanning electron microscopy.