Study On The Extraction And Function Properties Of Nostoc Sphaeroids K(?)tz Polysaccharides

Nostoc sphaeroids kutz belongs among the nostoc genera of cyanophyta nostoc families, which is a kind of edible algae grown in rice field, it is mainly distributed in Zoumaping town of Hefeng city in Hubei province. It is known as traditional precious wild food and drug dual-use algae, which once is called as fairy vegetable or fairy rice in our country. As reported, it is beneficial to eyesight, antipyretic, intestines, stomach, eliminating phlegm, tiredness and nyctalopia due to abundance of polysaccharides. Howerver, the physicochemical properties and composition of Nostoc sphaeroids kutz polysaccharides is still limited. In addtion, the mechanism of function was unclear.To establish foundation for industrial and medical applications of Nostoc sphaeroids kutz polysaccharides, the present study focus on the extraction, separation, purification and physicochemical and functional properties of Nostoc sphaeroids kutz polysaccharides. The main research results are as following:1. Extraction of Nostoc sphaeroids kiitz polysaccharidesThe yield of Nostoc sphaeroids kutz polysaccharides can be greatly increased by pretreatment with alkali-enzyme. The pH value of the extraction solution was adjusted to neutral until Nostoc sphaeroids kutz incubated with 0.4 mol/L NaOH at 40℃for 2 hours. Then the solution incubated again at 40℃for 10 hours after adding 1.0 mg liquid papain to per 100mg Nostoc sphaeroids kutz. Subseqentenly, distilled water was added with the ratio of 1:300 of Nostoc sphaeroids kutz dry weight. This extaction solution incubated at 90℃for 2 hours and repeated two times. The result showed that the yield of the polysaccharide was 47.56%, which was 2.12 folds compared with control treatment.2. Separation and purification of Nostoc sphaeroids kutz polysaccharidesThe Nostoc sphaeroids kiitz polysaccharides can be separated well under the combination of enzyme and sevag reagent. sevag The effects on the polysaccharides loss and decolouring was excellent through the sevag reagent method with 6 or 7 repeat.Over 99% Nostoc sphaeroids kiitz polysaccharides was purified by CTAB solution.It was hard to be seperated fractionately for Nostoc sphaeroids kiitz polysaccharides by DEAE-C-52, Sephadex G100, Sephadex G200, Sepharose 6B or Sepharose CL-4B filtering.3. Chemical composition and physicochemical properties of polysaccharides in Nostoc sphaeroids kutzThe polysaccharide in Nostoc sphaeroids kutz is a kind of acid polysaccharide, which contains Man,Rha,GlcA,GalA,Glc,Gal,Ara. The uronic acid content is 12.80±0.56%, the Neutral sugar content is 66.66±0.86%.The molecular is heavy with a scattered weight:Mw (9.564×106dal), Mn (5.634×106dal), and Mw/Mn (1.698). The proportion of C, H and O is 39.53%,7.08%,53.37%, respectively. In addition, the polysaccharide of Nostoc sphaeroids Kutz contains rich minerals. In the pattern of circular dichroism spectrum, there is a positive spike at 200nm, and a negative spike at 215nm. However, no more details about the secondary structure can be observed due to lack of polysaccharide which is applied in comparison. Moreover, the X diffraction pattern demonstrates that crystallization account for 29.97% in the polysaccharide structure.4. The solution and rheology feature of polysaccharide in the Nostoc sphaeroids kutzPolysaccharide of Nostoc sphaeroids kutz is soluble in water especially with high temperature. In addition, its solution is enhanced by acid. An opposite effect occur in alkali surrounding and mineral salt of lor 2 Valence.Due to its distinguished rheology, the potential appliment in food is addictive. Compared with xanthan gum, the viscosity is similar when the density is under 0.5%, and it is notably lower when the density is above 0.5%. It is more stable than xanthan gum when mixed with salt ion of 1 or 2 Valence In contrast, the polysaccharide is more inclined to affect by the high temperature.5.The investigation of physiological function to polysaccharides in Nostoc sphaeroids kutzThe capacity of anti-oxidation of Nostoc sphaeroids kiitz polysaccharide is weak by index of deoxidation capacity, the capacity of eliminating·OH and O2. The similar results showed that the polysaccharides could neither promote indicators of the activity of antioxidant (such as SOD and GSH-PX enzyme) nor reduce the malondialdehyde content in the tumor-burdened mice.6. Effect on tumor inhibition and immunity of mice in vivo.Nostoc sphaeroids kutz Polysaccharides can remarkably inhibit the tumor dependent on dose. For instant, the rate of tumor inhibition was 29.91%,38.24% and 64.08% by 50 mg/kg.d,100mg/kg.d and200mg/kg.d, respectively.Nostoc sphaeroids kutz Polysaccharides can restrain the cellular immunity descended by S180 tumor. Compared with tumor group, the rate of lymphocyte transformation of the cellular immunity of normal group, Cy group and high polysaccharides doses group are increased markedly. The NK cell activity can be inhibited remarkably in Cy and polysaccharides high doses group. DHT of mice in Cy and polysaccharides high doses group was higer than that in model group, sugging the both can inhibit the decrease of DHT in mice with tumor.Nostoc sphaeroids kutz Polysaccharides can promote index of the decrease of thymus. Nostoc sphaeroids kutz Polysaccharides can remarkably descend the thymus index.Nostoc sphaeroids kutz Polysaccharides can inhibit the increase of PLT in blood of mice with tumor. Except low dose of Polysaccharides group, the other groups can descend the amount of platelet. In addition, the amount of platelet of high dose of Polysaccharides group is similar with NC group in mice. The results indicated tumor can be inhibited by Nostoc sphaeroids kiitz Polysaccharides.The blood making can be destroyed by Cy therapy. However, RBC and hemoglobin have not obciously change by Nostoc sphaeroids kutz Polysaccharides, neither anemia arised from tumor nor hematopoietic damage by Cy.Nostoc sphaeroids kutz Polysaccharides has not obviously effect on the index of liver and kidney of mice with tumo. The tumor cells in tumor tissue were died by supplying the Nostoc sphaeroids kutz Polysaccharides. Furthmore, it didn't damage the biopsy of liver and kidneyNostoc sphaeroids kutz Polysaccharides didn't evidently promote or inhibit the increase of liver index and kidney index which arise from tumor. See from the biopsy, Nostoc sphaeroids Kutz Polysaccharides can kill a large area of tumor cell, and it showed from the biopsy of liver and kidney that Nostoc sphaeroids Kutz Polysaccharides didn't damage the biopsy of liver and kidney.