Removal Processing of Impurities from Mycelia Polysaccharide of Inonotus obliquus and Its Inhibition Effect on α-Glucosidase
Removal process of impurities from the crude polysaccharide extracted from Inonotus obliquus mycelia and its influence on the hypoglycemic activity of polysaccharide in vitro was investigated with various methods,including trichloroacetic acid(TCA)precipitation,Sevage technology,TCA n-butanol treatment,enzyme and enzyme-assisted extraction for the deproteinization as well as activated carbon,hydrogen peroxide and macroporous resin for the depigmentation.By comparing the removing effectiveness obtained from different processing methods and analysis of its effect on the α-glucosidase activity in vitro,it was found that a combined treatment of enzyme and TCA-n-butanol was mostly effective for the deproteinization,in which the removal rate of proteins was(75.93±0.89)%and the retention rate of polysaccharide was(71.88±5.32)%.Inhibition rate of α-glucosidase activity due to the above processing was 31.13%when the polysaccharide had a concentration of 10 mg/mL.The optimum condition for depigmentation using orthogonal treatment of S-8 macroporous resin was found,on the other hand,revealing its contents as follows:a resin dosage of 2 g,a temperature of 30 ℃ and a time of 6 h which showed a depigmentation rate of polysaccharide with a value of(78.31±1.34)%and a retention rate of polysaccharide with a value of(90.79±5.46)%.The inhibition rate of α-glucosidase activity due to the above treatment was 44.97%when polysaccharide was at a concentration of 10 mg/mL.Our results thereafter demonstrated that the treatment using enzyme and TCA-n-butanol combined with S-8 macroporous resin was the best method for removing proteins and pigments to gain purified polysaccharides having the inhibitory activity on α-glucosidase much better than other removal methods reported so far.