Study On The Extraction,Purification And Antioxidant Activity Of Rana Dybowskii Jelly Coats Polysaccharide

Rana chensinensis,with many biological activity functions,caused extensive attention and research of domestic and foreign scholars.The jelly coats of the Rana chensinensis also play an important role in the hatching of the eggs of the Rana chensinensis.It has the effect of regulating the concentration of calcium ions,so that the eggs can reach the best fertilization state and the ability of resisting the environmental change,and ensure that the frog eggs can maintain normal Osmotic pressure,prevent the invasion of bacteria,and provide nutrition for the egg supply.Different types of amphibian jelly coats have different morphology and layers,whose chemical composition is also different.Rana chensinensis jelly coats consist mainly of mucopolysaccharide and protein.In this paper,some of the bioactive substances were studied by using Rana chensinensis jelly coats as raw material.Because of the high nutritional value and medicinal value of Rana chensinensis,it has been very important for scholars to pay attention to its main products,such as Rana oil,Rana chensinensis,Rana chensinensis oil and frog meat,and so on.The content of moisture,ash,fat and protein in the eggs of Rana chensinensis was determined in this paper.The moisture content was determined by direct drying method.The content of total ash and acid-insoluble ash content were determined by direct drying method.The content of fat was determined by Soxhlet extraction method.The protein content was determined by Coomassie brilliant blue method.The results showed that the water content of jelly coats was between 72% and 79%,the total ash content was between 0.59% and 0.94%,the content of acid insoluble ash was between 0.06% and 0.14%,and the fat content was between 1.6% and 3.5%,the protein content was between 147-175 mg/g..Phenylisothiocyanate as derivatizing reagent was used to determine the amino acid type and content.The differences of types and contents of amino acids in the Jelly coats of different origin and different frog ages were compared.In addition to tryptophan,other amino acids were detected,with the highest amino acid content was up to 10.004 mg/g,the essential amino acids content was 24.57%.The effects of enzyme dosage,ratio of liquid,PH concentration,enzymolysis time,and their interaction rate were studied by central composite design,and the extraction process was optimized.The predicted results from our model showed that the optimized condition was: 74.55 mg/g for papain amount,7.67 for PH,52.55? for temperature and 2.09 h for total extraction time.Using this method,the maximum extraction amount easure was 23.84±0.07 mg/g.This study provides an effective method for the extraction process of polysaccharide in Jelly coats.Polysaccharide was deproteinized and dialyzed,and the two components were obtained by cellulose DEAE-52 ion exchange column chromatography.The polysaccharide I and the polysaccharide II were collected to collect the polysaccharide I,Gel Sephadex G-100 column chromatography was used to obtain a single symmetrical peak shape 138.6mg.The results showed that the polysaccharide I was a single component.The basic physical and chemical properties of polysaccharide I were determined by the determination of solubility,phenol-sulfuric acid reaction,fenilin reaction and ninhydrin reaction.The results showed that polysaccharide I had the same property of polysaccharide,no protein and small molecule oligomerization Sugar and other residues;by infrared spectroscopy(IR)method results showed that refined polysaccharide I had a typical absorption of polysaccharide compounds and the monosaccharide composition was determined by gas chromatography.The content of monosaccharides was mannose(MAN)30.72%,glucose(GLU)29.13% and galactose(GAL)32.47%.The moisture absorption,moisture retention and in vitro of antioxidant activity of polysaccharide I were measured.Glycerin,hyaluronic acid and polyethylene glycol(PEG-400)were used in ascontrast,and the moisture absorption and moisture retention of polysaccharide I were measured in 24 hour.The results showed that the polysaccharide I had a certain moisture absorption and moisturizing ability.Compared with the three kinds of moisturizing agents,the average absorbency of polysaccharide I in 24 h was: glycerol > hyaluronic acid > polysaccharide I > PEG-400.The moisturizing ability in 24 h of polysaccharide and three kinds of commonly was: hyaluronic acid > glycerin > polysaccharide I > PEG-400.The ascorbic acid was used as the contrast,and the Oxidation resistance of polysaccharide I was determined.The results showed that polysaccharide I scavenging ability for O2-· is the strongest,and the scavenging ability of ·OH was relatively poor.Both of free radical scavenging capacity was lower than that of ascorbic acid.But still had a good antioxidant activity,it can be considered for skin care product development research.