Optimization of extraction, characterization and antioxidant activity of polysaccharides from Brassica rapa L.
The root of Brassica rapa L. has been traditionally used as a Uyghur folk medicine to cure cough and asthma by Uyghur nationality in Xinjiang Uygur Autonomous Region of China. In the present study, therefore, extraction optimization, characterization and antioxidant activity in vitro of polysaccharides from the root of B. rapa L. (BRP) were investigated. The optimal extraction conditions with an extraction yield of 21.48 ± 0.41% for crude BRP were obtained as follows: extraction temperature 93°C, extraction time 4.3h and ratio of extraction solvent (water) to raw material 75 mL/g. The crude BRP was purified by chromatographic columns of DEAE-52 cellulose and Sephadex G-100, affording three purified fractions of BRP-1-1, BRP-2-1 and BRP-2-2 with average molecular weight of 1510, 1110 and 838 kDa, respectively. Monosaccharide composition analysis indicated that BRP-1-1 was composed of mannose, rhamnose, glucose, galactose and arabinose, BRP-2-1 was composed of rhamnose, galacturonic acid, galactose and arabinose, and BRP-2-2 was composed of rhamnose and galacturonic acid in a molar ratio of 1.27: 54.92. Furthermore, the crude BRP exhibited relatively higher antioxidant activity in vitro than purified fractions; hence, it could be used as a natural antioxidant in functional foods or medicines.
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; College of Food Science and Pharmacy, Xinjiang Agricultural University, Urumqi 830052, PR China.
Wei
W
Wang
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Xiaoqing
X
Wang
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Hong
H
Ye
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Bing
B
Hu
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Li
L
Zhou
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China; Institute of Food Science and Nutrition, University of Sargodha, Sargodha, Pakistan.
Saqib
S
Jabbar
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: zengxx@njau.edu.cn.
Xiaoxiong
X
Zeng
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: wbshenh@njau.edu.cn.
Wenbiao
W
Shen
D000704:Analysis of Variance; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D029741:Brassica rapa / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008970:Molecular Weight; D010084:Oxidation-Reduction / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D011134:Polysaccharides
Antioxidant activity; Brassica rapa L.; Characterization; Extraction; Polysaccharide