Preparation and antioxidant property of extract and semipurified fractions of Caulerpa racemosa
- 696 Downloads
A microwave-assisted extraction method has been developed for the extraction of phenolic compounds from the green alga, Caulerpa racemosa. An L18(3)5 orthogonal experimental array was designed to optimize the extraction conditions. Total phenolic content was determined by Folin–Ciocalteu method. Under the optimized conditions (microwave power, 200 W; ethanol concentration, 60%; extraction time, 40 min; extraction temperature, 50°C; solvent-to-material ratio, 40 mL g−1), the maximum total phenolic content reached 67.89 ± 3.88 mg 100 g−1 dried sample. The crude ethanolic extract was further purified by liquid–liquid partition to afford two fractions, of which the ethyl acetate-soluble fraction (EAF) exhibited the strongest antioxidant activity in the hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays and reducing power. EAF was further divided into four subfractions, designated as EAF1 to EAF4, by silica gel vacuum liquid chromatography. The antioxidant capacity of the subfractions was in the following order: EAF1>EAF2>EAF4>EAF3. The results of IR spectral and HPLC analysis, including the research on the correlation between antioxidant capacity and total phenolic content, suggested that phenolic compounds of medium polarity were the major contributors to the antioxidative activity of C. racemosa. The present findings might contribute to a rational basis for the use of phenolic-rich fractions and subfractions as natural antioxidants in different food/pharmaceutical products.
KeywordsCaulerpa racemosa Chlorophyta phenolic compounds Microwave-assisted extraction (MAE) Antioxidant activity
This work was financed by National Natural Science Foundation of China (No.81001393), the State-level Spark Program (2010GA700088), and Zhejiang Provincial Natural Science Foundation (No.Y2110636). The authors thank Dr. Changfeng Chi for her critical reading and corrections of the manuscript.
- Jin M, Cai YX, Li JR, Zhao H (1996) 1,10-Phenanthroline–Fe2+ oxidative assay of hydroxyl radical produced by H2O2/Fe2+. Prog Biochem Biophys 23:553–555Google Scholar
- Lu X, Webb M, Talbott M, Van Eenennaam J, Palumbo A, Linares-Casenave J, Doroshov S, Struffenegger P, Rasco B (2010) Distinguishing ovarian maturity of farmed white sturgeon (Acipenser transmontanus) by Fourier transform infrared spectroscopy: a potential tool for caviar production management. J Agric Food Chem 58:4056–4064PubMedCrossRefGoogle Scholar
- Luo HY, Wang B, Yu CG, Qu YL, Su CL (2010a) Evaluation of antioxidant activities of five selected brown seaweeds from China. J Med Plant Res 4:2557–2565Google Scholar
- Luo HY, Wang B, Yu CG, Xu YF (2010b) Optimization of microwave-assisted extraction of polyphenols from Enteromorpha prolifra by orthogonal test. Chin Herb Med 2:321–325Google Scholar
- Wang B, Yu CG, Luo HY, Qu YL, Yang LY (2010) Studies on the preparation and antioxidant properties of enzymatic hydrolysate from Dasyatis akajei by papain. Food Sci Technol Int 10:113–118Google Scholar