Modification Of High Molecular Weight Polysaccharides From Hericium Erinaceus Based On Structure-activity Relationship

Hericium erinaceus is a kind of famous edible and medition fungus,helping digestion,and can treat neurasthenia,gastritis,gastric ulcer.Hericium erinaceus polysaccharide is one of the most active components,which can improve immunity,anti-oxidation,anti-tumor,anti-aging,hypoglycemic and other effects.It is a kind of immune active agent.However,because of the high viscosity of the polysaccharide,it is difficult dissolve in water,which limits the development and utilization of the polysaccharide.We can use physical or chemical methods to modificate or degradate of this polysaccharide,thus we can attach a series of different molecular,high solubility of the fragment.It will further expand the application of polysaccharides in food,health care products and clinical.But recent studies have shown that it has the direct effect of killing tumor cells.No matter what kind of action,the research results have shown that the anti-tumor effect is closely related to its structure and its advanced conformation.We used a combination of chemical analysis,spectral analysis and modern instrumental analysis techniques to identify the primary chemical structure and the senior carbohydrate chain conformation,and we also discuss its in vitro immunity.Therefore,we study the intrinsic link between its structure and its in vitro immunity.It will lay the foundation for further quantitative structure-activity relationship studies and computer simulations of carbohydrate chain conformation,and to provide theoretical and material basis for subsequent molecular mechanisms of antitumor effect.Specific research content is divided into the following parts:1 Study on Preparation and in vitro activity of ultrasonic degradation of hericium erinaceus macromolecular beta glucanIn this part,H6PC20 as raw materials for degradation by ultrasonic technology,ultrasonic time,the concentration of polysaccharide,effect of intensity ultrasonic effect on the ultrasonic degradationwas investigated,and then investigated the effect of UH6PC20 in vitro stimulated release of NO macrophage cells.In order to find out the high in vitro immunity,small molecular weight,high solubility of molecular fragments.The solubility of polysaccharide after ultrasound was significantly improved,increased from 3g/L to 30.2 g/L,the molecular weight from 2.39×10⁶ Da to2.80×10⁵ Da,the content of polysaccharide of H6PC20 was 94.99%,the content of polysaccharide UH6PC20 was 94.72%,the basic content of polysaccharide has no obvious changed.2 Studies on the chemical structure and conformation changes of hericium erinaceus polysaccharides before and after ultrasonic degradationTo determine the monosaccharide composition of H6PC20 and UH6PC20 by complete acid hydrolysis.Methylation analysis further confirmed the polysaccharide residue ratio.Infrared spectroscopy scanning indicated the characteristic absorption peaks and the sugar residue configuration of H6PC20 and UH6PC20 component.NMR analyzed the sugar residue type,the connection sequence and substitution sites,which verified each other with the results of chemical analysis.The experimental results have showed that H6PC20 and UH6PC20 were composed of glucose,and the chemical analysis indicated that each of them contains three types of sugar residue,the proportion of them were（Terminal:1-3:1-3-6）about 1:2.56:0.9 and 1:2.45:0.97.IR scanning also showed that they had characteristic absorption peaks of polysaccharide,and the structure wasβ-D-pyranose.NMR detection further speculated that the main chain structure of each component wasβ-（1→3）-D-pyran-glucan while had branches at C₆.The results showed that ultrasonic treatment had no significant effect on the connection mode and structure of polysaccharide.Comparied the change of maximum absorption wavelengthλmax that contributed by the complexes formed between H6PC20 and UH6PC20 with congo red respectively under the condition of different concentrations of Na OH solution through congo red experiments.Therefore,inferred the helical conformation of the sugar chain.The maximum absorption wavelength was about 350nm,which indicated that the polysaccharide had more branch chain or longer chain.Using the size exclusion chromatography multiangle laser light scattering instrument differential refractive index capillary viscometer（SEC-MALLS-RI-Visco）quadruple device was used to characterize the dilute solution behavior of Hericium erinaceus in solution.Based on the experimental data,we can get the chain conformation parameter and Mark-Houwink equation were obtained by theoretical calculation.The results showed that the strain was three helical chain conformation.Observed the surface morphology distribution of H6PC20and UH6PC20 by AFM and speculated their spatial conformation.XRD experiments detected the purified polysaccharide chain’s regular arrangement of H6PC20 and UH6PC20 and also examined their crystallographic information.The sugar chain height of the natural lentinan matched with the crystal parameters（crystallite size）measured by XRD,which were about 1.7nm.Therefore,all these could further confirm that each fraction had triple-helical spatial conformation.3 Study on preparation technology and in vitro activity of macromolecularβ-glucan from Hericium erinaceusIn this part,the polysaccharide of Hericium erinaceus was degraded by different acids.TFA was selected to degradate polysaccharides.In this paper,we first discuss the effect of acid concentration and acid degradation time on the degradation efficiency.When the acid concentration is the same,the degradation time is longer and the molecular weight is smaller.4 Comparison and analysis of large molecular polysaccharides from Hericium erinaceus from different strainsThe difference of macromolecular polysaccharide on twelve different Hericium erinaceus strain solid fermentation and liquid fermentation were analyzed.The research shows that different varieties of polysaccharide vary greatly,polysaccharide of mycelia produced in 0627 and 0608 strains were the highest,0.3%.polysaccharide liquid fermentation mycelium produced by 0605 the strain was the highest,2.89%.analysis of the HPSEC and HPAEC patterns of different varieties based on polysaccharides,established the fingerprint composition characterization of Hericium erinaceus polysaccharide and monosaccharide molecular weight distribution.To study the effect of solid fermentation and liquid fermentation mycelium polysaccharide stimulate macrophages to produce NO,found that Gutian in vatro immunological activity,the mycelium liquid fermentation strains of huazhong polysaccharide was much better than other.It has certain correlation between immunological activity of polysaccharide and monosaccharide composition of different strains and the molecular weight.