Extraction,Purification And Antioxidant Activity Of Polysaccharides From Mosla Chinensis Maxim.cv.Jiangxiangru

Botanical polysaccharides were widely distributed in nature. The researchers found that plant polysaccharides had many kinds of biological activities and functions, especially in terms of scavenging free radical. A variety of reactive oxygen species such as hydroxyl radicals and superoxide anion radicals were produced by oxidative metabolism during life activities. These free oxygen radicals were almost related to most common human diseases such as autoimmune diseases, atherosclerosis sclerosis and diabetes. Thus, the studies of antioxidant activities of plant polysaccharides had an important practical significance for developing new natural antioxidants. The main research results are as follows:1. Extraction and optimization of polysaccharides from Mosla chinensis-jiangxiangruCrude polysaccharides from Mosla chinensis-jiangxiangru were extracted by using hot water with the assistance of ultrasonic waves. Three factors of ultrasonic power, ultrasonic time and liquid to solid ratio were selected to optimize the extraction process with the method of response surface test. Under the optimal extraction conditions of ultrasonic time 8 min, ultrasonic power 224 W and liquid to solid ratio 39:1, the polysaccharide yield was 7.62%, which was very close to the predicted value of 7.67%.2. Study on the decoloration of polysaccharides from Mosla chinensis-jiangxiangruThe decoloration effects of polysaccharides which were bleached by hydrogen peroxide were better than AB-8 macroporous resin and granular activated carbon. Hydrogen peroxide was selected as the bleaching agent. To study the effects of bleaching temperature, bleaching time, pH, hydrogen peroxide dosage on decoloration of crude polysaccharides, orthogonal experiment was used to optimize decoloration conditions. The results showed that the optimal decoloration temperature, duration, pH and decolorant dosage were 70℃,150 min,10.0 and volume fraction of 16.5%, respectively. Under these conditions, the decoloration rate was 82.83% and 80.52% of polysaccharides holding rate was recovered. Qualitative analysis showed that the polysaccharides had the similarly infrared absorption spectrum. The polysaccharides existed α-type glycoside bond absorption peak. The polysaccharide was bleached by hydrogen peroxide of 16.5% and its infrared absorption spectrum existed a-type glycoside bond absorption peak. The a-type glycoside bond absorption peak disappeared when the amount of hydrogen peroxide reached 40.0%.3. Study on the deproteinization of polysaccharides from Mosla chinensis-jiangxiangruTo compare the effects of removing protein by different methods, sevag method, polyamide, granular activated carbon, trichloroacetic acid were used. The results showed that polyamide method was better than others.4. Purification and physicochemical property of polysaccharides from Mosla chinensis-jiangxiangruJXR-1 and JXR-2 were isolated by using DEAE Sepharose CL-6B column. The yields of the two major polysaccharide components were 37.60% and 42.30%, respectively. They were both acidic polysaccharides. UV scanning spectrum of the two polysaccharides indicated that both proteins and nucleic acids were removed. The infrared spectrum of JXR-1 and JXR-2 showed that they contained characteristic absorption peaks of carbohydrate. The high performance gel permeation chromatography of JXR-1 and JXR-2 indicated that they were non-homogeneous polysaccharides. JXR-1 contained three components with molecular weights of 12250,1103 and 244 Da. JXR-2 contains three components with molecular weights of 47941,2361 and 470 Da. The monosaccharide composition was analyzed by high-performance anion-exchange liquid chromatography. The results showed that the monosaccharide compositions of JXR, JXR-1, JXR-2 were similar, containing rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid and glucuronic acid. JXR mainly contained galactose and glucose. JXR-1 and jxr-2 mainly contains arabinose, galactose and glucose.5. Study on the antioxidant activities of polysaccharides from Mosla chinensis-jiangxiangru in vitroThe results of three antioxidant systems of scavenging hydroxyl free radical tests, scavenging superoxide anion free radical experiments and reducing power tests indicated that polysaccharides from Mosla chinensis-jiangxiangru had some antioxidant activity. And the antioxidant activity of JXR-2 was stronger than JXR-1.