2.2 Isolation and purification of polysaccharide
Briefly, the dry three-year roots of Radix ginseng (2,000 g) were
smashed into crude powder (60-80 mesh) and extracted three times with
water (20 L) by continuously stirring at 80 °C for two hours each time.
The combined aqueous extracts were filtered through a cotton cloth bag
and centrifuged (1,500 g for 15 min) and were subsequently concentrated
in a rotary evaporator at 60 °C. Then, the ethanol solution was to a
final concentration of 80%. The sediment was dissolved in water,
continuously stirred at 4 °C for 12 hours, and the precipitate was
removed by centrifugation (1,500 g for 15 min). The aqueous extract was
then filtered and concentrated, followed by the addition of Sevage
reagent (butanol and chloroform at a 1:4 ratio) to deproteinate the
sample (Huang, Li, Wan, Zhang, & Yan,
2015). Then, the supernatant was concentrated to a proper volume under
reduced pressure and lyophilized to get the GP.