Physicochemical properties and biological activities of polysaccharides from Lycium barbarum prepared by fractional precipitation.
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Traditional separation and purification process of Lycium barbarum polysaccharides (LBP) includes water extraction, alcohol precipitation, deproteinization and ion-exchange column chromatography, which is complicated and time-consuming. In our study, retentate LBP-I and dialysate LBP-O were obtained from LBP by water extraction, alcohol precipitation and deproteinization. LBP-I was separated by fractional precipitation and three fractions (LBP-I-1, LBP-I-2 and LBP-I-3) were obtained. The three fractions were further purified by gel permeation chromatography to LBGP-I-1, LBGP-I-2 and LBGP-I-3 with yields of 0.05%, 0.03%, and 0.19%, respectively, which are higher than yields by traditional method. The physicochemical properties, biological activities of LBGP-I-1, LBGP-I-2 and LBGP-I-3 were investigated. The results indicated that LBGP-I-1 (3.19 × 104 Da) consists of arabinose (21.95%), glucose (51.22%) and galactose (17.07%); LBGP-I-2 (2.92 × 104 Da) mainly consists of arabinose (19.35%), glucose (32.26%) and galactose (35.48%); LBGP-I-3 (9.12 × 104 Da) mainly consists of arabinose (48.15%) and galactose (44.44%). LBGP-I-1 and LBGP-I-2 were different from the components purified by traditional method. LBGP-I-3 could most significantly enhance macrophages NO, phagocytic capacity, and acid phosphatase. LBP-O exhibits the strongest anti-oxidant activities in vitro. These results provided a reference for applications of Lycium barbarum polysaccharides which would benefit the development of industry and agriculture.