Study On The Extraction, Structure And Preparation And Biological Activity Of Auricularia Auricularia Polysaccharide Zinc Comple

Auricularia trichomoniae belongs to the genus auricularia,the class agaricus,and is a typical gelatinous fungus,also known as white-back auricularia and thick auricularia.It is born in tropical and subtropical areas and widely distributed throughout the country.The polysaccharide was the main active component,and its content was up to 70%.Relevant studies have shown polysaccharides have anti-cancer,anti-mutation,anti-tumor,immunomodulatory,anti-oxidation,anti-coagulation,hypoglycemic,hypolipidemic and other functions.In this paper,we have carried on the systematic research on the extraction technology of auricularia auriculata polysaccharides and the optimal conditions.The crude polysaccharide was isolated and purified,and APP44 with high antioxidant activity was selected.The physical and chemical properties and structure of the compound were studied,and the effects of APP44on blood sugar and lipid were investigated.The optimal conditions of compound APP44 and Zn were investigated,and the structure and antioxidant activity of polysaccharide zinc complex were studied.The results are as follows:The first part is the study on extraction technology and optimization of polysaccharides from auricularia auriculata.Single-factor experiments and response surface design were used to optimize the optimal process parameters for each method.The extraction methods of hot water were:40/1（m L/g）,extracting time 125 min,extracting temperature 95℃,APP yield was15.58%.The methods of ultrasonic extraction were:liquid-solid ratio 40/1（m L/g）,extraction temperature 82℃,ultrasonic time 50min,ultrasonic power 300W,and the yield of APP was 32.64%.The extraction methods of microwave were as follows:liquid-solid ratio 40/1（m L/g）,extraction temperature 91℃,microwave time 6.5min,microwave power 220W,and the yield of APP was 27.26%.From the perspective of economic benefit and practical operation,ultrasonic method was selected as the main method to extract polysaccharides from auricularia auriculata.The second part is isolation,purification and structural characterization of polysaccharides from auricularia.The DEAE-52 cellulose column was used for the purification of crude polysaccharide from auricularia,yielding APP1-APP5 components,and the Sephadex G-200gel column was then employed to obtain APP11-APP55 components,thus completing the structural characterization and purification process.APP44’s antioxidant activity exhibited the most impressive scavenging capacity on DPPH·and ABTS⁺·.UV spectrum analysis of APP44showed no absorption peak in the range of 200nm-400nm,which was a single pure polysaccharide component.The characteristic absorption peak of polysaccharide in APP44 was analyzed by infrared spectroscopy.The rmogravimetric analysis showed that APP44 had a significant weight loss peak in the range of 900-1050℃,with a weight loss rate of approximately 90.7%.The molecular weight of APP44 was determined at 407380Da by means of high-performance gel permeation chromatography（HPGPC）.The main components of APP44 are mannose（Man）,xylose（Xyl）,glucose（Glu）,glucuronic acid（Glc A）and glucosamine（Glc N）,with a molar ratio of 4.98:2.94:1.5:1:0.18,and a small amount of ribose,rhamnose,galactose and caramel.The third part is the study on hypoglycemic and hypolipidemic activity of polysaccharides from auricularia auriculata.In vitro,APP44 inhibitedα-glucosidase andα-amylase activities to a certain extent,and reached saturation at the concentration of 1.6 mg/m L.APP44 could effectively inhibit the activity of pancreatic lipase,and reached saturation after 35%inhibition at the concentration of 8 mg/m L.At the same time,it has the binding ability with sodium glycholate and sodium taurine cholate,and the maximum binding rate is 8mg/m L.In vivo,the maximum tolerable concentration（MTC）of APP44 was 500μg/m L.The hypoglycemic effect of APP44 on zebrafish with high glucose and fat was 31.9%when pioglitazone（20μg/m L）was used as positive control.Atorvastatin calcium（20μg/m L）was used as positive control.The triglyceride lowering effect of APP44 was 66.67%,and its cholesterol lowering effect was 54.67%.The fourth part is the study on preparation and antioxidant activity of polysaccharide-Zinc complex of trichomyces auriculata.Experiments of single factor and orthogonal design yielded the most advantageous recombination conditions for APP44-Zn.The composite time was 2h,the composite temperature was 70℃,pH4.5,Zn SO₄ dosage was 15m L,and the binding rate of APP44-Zn was（64.64±0.67）%.UV spectrum analysis showed that active groups such as-OH in APP44 combined with Zn,which made the absorption strength of complex stronger than APP44.Infrared spectra show that the combination of APP44 and Zn makes the absorption peak redshifted.The scanning electron microscope（SEM）showed that APP44 was a large block with a slightly rough surface,while APP44-Zn was a small flat sheet with a granular surface.The energy dispersion spectra showed that the binding rate of Zn was higher except for C and O elements after the combination of APP44 and Zn.Studies on antioxidant activity showed that APP44 and APP44-Zn had certain scavenging ability on DPPH·,ABTS⁺·,·OH and O₂^-·,and the compound APP44-Zn had better free radical scavenging ability and higher antioxidant activity.