title: Extraction, Structural Characterization, and Potential Antioxidant Activity of the Polysaccharides from Four Seaweeds.
abstract: Four seaweed polysaccharides were extracted fromSarcodia ceylonensis,Ulva lactucaL.,Gracilaria lemaneiformis, andDurvillaea antarctica, respectively, by microwave-assisted extraction. The effect of three significant variables (extraction time, extraction temperature, and the ratio of water to raw material) on the process for extracting polysaccharides was investigated, along with the optimization of the extraction using the response surface method (RSM) with a Box-Behnken design. The polysaccharide structure, monosaccharide composition, degree of sulfation, and molecular weight (MW) distribution were analyzed by infrared (IR) spectrometry, gas chromatography (GC), and high-performance gel permeation chromatography (HPGPC). IR spectrometry showed thatSarcodia ceylonensispolysaccharide (SCP),Ulva lactucaL. polysaccharide (ULLP), andDurvillaea antarcticapolysaccharide (DAP) were all sulfated polysaccharides and, exceptGracilaria lemaneiformispolysaccharide (GLP), all belong to β-pyranosidic polysaccharides. The average molecular weight (MW) of SCP, ULLP, GLP, and DAP was 466, 404, 591, and 482 kDa, respectively. The quantitative and comparative results with external standards indicated that the main monosaccharide in SCP and ULLP was mannose; and GLP and DAP were mainly composed of galactose and glucose, respectively. Then the in vitro antioxidant activity of all of the polysaccharides was evaluated using different assays-2,2-azino -bis (3-ethylbenzthiazoline-6- sulfonate) (ABTS), hydroxyl radical, nitrite scavenging capacity, and reducing power-and the relationship between their antioxidant activity and chemical characteristics were also examined. ULLP presented the highest ABTS radical scavenging activity; ULLP, SCP and DAP also showed a strong effect on the ABTS radical scavenging activity. SCP and ULLP exhibited excellent hydroxyl radical scavenging activities, about 83.33% ± 2.31% and 80.07% ± 2.17%, respectively, at 4 mg/mL. The reducing power of DAP was relatively more pronounced than that of the three other polysaccharides. However, the nitrite scavenging activities of the four seaweed polysaccharides were weaker than other antioxidant activity (ABTS), hydroxyl radical scavenging capacity, and reducing power. In addition, GLP exhibited lower activities than the other three samples in all of the tests for the antioxidant activity.
authors.affiliation: Department of Food Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China. hejzgd@163.com.
authors.forename: Jinzhe
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Food Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China. xuyaoyang1030@126.com.
authors.forename: Yaoyang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Zhejing Fangyan Test Group Co., Ltd., Hangzhou 310018, Zhejiang, China. see271@126.com.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Food Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China. sunpeil388@163.com.
authors.forename: Peilong
authors.initials: P
authors.lastname: Sun
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D010084:Oxidation-Reduction / Q000187:drug effects; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology; D012624:Seaweed / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D011134:Polysaccharides
keywords: antioxidant activities; composition; extraction; molecular weight (MW); polysaccharide; seaweed