Chromatographic determination of polysaccharides in Lycium barbarum Linnaeus

Antioxidative activity of polysaccharide fractions isolated from Lycium barbarum Linnaeus

“…A method based on Wang et al [13] was used to extract polysaccharides from L. barbarum sample. Briefly, a 10-g of dried sample was mixed with 100 mL of deionized water, after which the solution was homogenized for 1 min and heated in boiling water for 30 min.…”

“…The protein in crude polysaccharide was removed by protease to avoid interference in antioxidative activity based on a method described by Wang et al [13]. A 0.2-g of polysaccharide powder was dissolved in 40 mL of phosphoric acid buffered solution (50 mM and pH 8), followed by heating in a 60 • C water bath for 5 min, adding 1.0 mL of proteinase (2.5 U/mL, Type III from Bacillus L.) and reacting at 60 • C for 4 h (pH 8).…”

“…The impurities in crude polysaccharide such as salts and those with MW < 3500 were further removed by dialysis based on a method by Wang et al [13]. Prior to dialysis, the membrane was cut into a size (10 cm × 5.4 cm) and immersed in deionized water for 30 min.…”

“…Both the neutral and acidic fractions of polysaccharides were prepared using a method described by Wang et al [13]. A 5-mL of deproteinated polysaccharide solution was poured into a glass column (30 cm × 2.4 cm) containing 5 g of resin DEAE-Sepharose CL-6B, which was equilibrated with 150 mL of deionized water before.…”

“…According to a report by Wang et al [13], a maximum content of polysaccharide could be obtained by controlling volume ratio of sample to solvent, precipitation temperature and time, and the most appropriate extraction condition was: sample to water ratio at 1:10, followed by heating in a 100 • C water bath for 30 min, concentrating to a small volume under vacuum, adding 95% ethanol with a volume 5-fold that of sample, precipitating at −20 • C for 8 h.…”