The Study Of Carboxymethylated And Sulfated Corn Fibre Gum Polysaccharides And Related Activities

In this paper,corn bran polysaccharide extracted from the corn fibre gum,and the corn bran polysaccharide was carboxymethyl and sulfation modified,then studied both antioxidant activity and anti-tumor of corn bran polysaccharide and polysaccharide derivatives.The corn bran polysaccharide was modified aiming to enhancing the antioxidant activity and anti-tumor activities.Ultrasonic method was chosen to extract corn bran polysaccharide,considered ultrasonic frequency,ultrasonic power,ultrasonic time and the reaction temperature as the factors carried out the repeated orthogonal experiment,ultrasonic power less impacted on the extraction rate.According to economic conditions and enforceability chose the optimal conditions was,ultrasonic frequency 60kHz,ultrasonic time 30min,the reaction time 60 ?.To investigate the influence of the carboxymethyl polysaccharide's degree of substitution and antioxidant activity,the optimal condition was NaOH 6mol/L,the reaction temperature 60? and reaction time 5h,the maximum degree of substitution 0.53,0.53,0.52,respectively.Investigated the optimal condition on the degree of substitution of Sulfated polysaccharide and antioxidant activity,the result was amino acid 2g,DMF 60mL and reaction time 2.5h,and obtained the maximum degree of substitution 2.46,2.35,2.71,respectively.The total phenolic content of both polysaccharide derivatives were lower than the original corn bran polysaccharide,and DPPH radical scavenging and ferrous ion chelating ability increased with the improved degree of substitution,and the two index levels were higher than the original polysaccharides.To study the relevant mechanism,real-time PCR was conducted to analyse the related genes in cancer cell A549 and HepG2,about the anti-tumor metabolism.casp3,casp8,casp9,p53,Bcl-2 and iNOS were the target genes.Obtained that the relative expression of casp3,casp8,casp9 and p53 genes treated by two polysaccharide derivatives in A549 and HepG2 were higher than the original polysaccharide-treated group;the expression levels of Bcl-2 and iNOS declinecd,significantly lower than the relative expression of polysaccharide-treated group.