Study On Structure-activity Relationship Of Biological Activity Of Sulfated Polysaccharides From Mollusks

Scallop polysaccharide(SP)and Clam polysaccharide(CP)were extracted from Scallop polysaccharide and Clam polysaccharide.Two kinds of polysaccharides were sulfated by chlorsulfonic acid-pyridine method to obtain 22% sulfated scallop polysaccharide(SSP1),32%sulfated clam polysaccharide(SSP2)and 36% sulfated clam polysaccharide(SCP).The basic composition,structure and biological activity of these five polysaccharides were studied.The main results are as follows:1 ? By changed the reaction ratio of anhydrous pyridine and chlorsulfonic acid,polysaccharide can bind different contents of sulfate,and the more sulfate bound,the higher degree of substitution.2?It can be seen from the infra-red spectrum,SSP1,SSP2 and SCP all have characteristic absorption peaks after sulfation.The monosaccharide composition showed that the polysaccharides mainly contained glucose before and after sulfated,and the amino sugars in sulfated polysaccharides decreased.The determination of molecular weight showed that sulfated polysaccharide could degrade and the molecular weight decreased.Scanning electron microscopy showed that the microstructure changed from the original fragment to the whole sheet with better integrity.NMR results showed that the sulfate group binding site may occur at C-6 position.Congo red experiment showed that the trihelix structure of scallop polysaccharides after sulfated disappeared,but the clams polysaccharide still had the trihelix structure.3.The five polysaccharides(SP,SSP1,SSP2,CP and SCP)showed no toxicity to macrophages(RAW264.7)at the concentration of 2.5-50 ?g /m L,and showed promoting effect with the increase of concentration.At the same concentration,the sulfated polysaccharides had a weakened effect on the proliferation of macrophages,and the more sulfate radical content,the stronger the inhibition effect.The content of neutral red,NO and TNF-? also confirmed that the immune activity of polysaccharides from mollusks decreased after sulfation.4.In vitro antioxidant activity showed that the scavenging ability of DPPH free radical and hydroxyl free radical of the sulfated scallop and clastella polysaccharide was higher than that of the non-sulfated polysaccharide,and the scavenging ability increased with the content of sulfated radical.The sulfated scallop polysaccharides showed antibacterial activity with the minimum inhibitory concentration of 20 mg/m L against all five bacteria.The minimum bactericidal concentration was 20 mg/m L for Bacillus cereus,Listeria monocytogenes and Staphylococcus aureus,and 30 mg/m L for Bacillus subtilis and Escherichia coli.In vitro antitumor activity showed that scallop and clam seed polysaccharides could inhibit human breast cancer cells(MCF-7)and kill tumor cells after sulfated.