Extraction And Purification Of Chondroitin Sulfate

Chondroitin sulfate, relative molecular mass from 10,000 D to 50,000 D, is an acidic polysaccharide composed of disaccharide units of glucuronic acid and aminohexose. Chondroitin sulfate distributing in various animal tissues has been proven to posses various biological activities such as adjusting immunity and fat metabolism, preventing infection, reducing the risk of heart diseases. Therefore, chondroitin sulfate has great application potentials in fields of food, medicine and cosmetic. Chondroitin sulfate extraction was studied. The appropriate conditions were that bovine nasal cartilage was soaked in 2% (w/v) NaOH / 2%(w/v) NaCl (1:4,v/v) solution 12 times as many as the weight of raw material at 40℃for 36h. Both pancreatin and papain were used to catalyze the hydrolysis of proteins in the fitrate. The results indicated that pancreatin had higher catalysis at pH 8.8 and 54℃for 10h, while papain had higher activity at pH6.8 and 40℃for 1h. The obtained hydrolysate was then removed by precipitation with 70% (v/v) ethanol solution. The results showed that the yield of chondroitin sulfate was 16.20% (w/w) and the glucuronic acid content in the extract was 44.67% (w/w). Ion-exchange method and ethanol precipitation were applied to purify chondrointin sulfate. The results indicated that glucuronic acid content in the refined product by ion-exchange (resin D218) adsorption was higher than that by ethanol precipitation. The appropriate purification conditions were that the extract dissolved in pH 6.0, 0.07 mol·L-1 sodium chloride solution was eluted with pH8.0,3.0mol·L-1 sodium chloride solution at 0.25 BV·h-1 and room temperature. The results indicated that the glucuronic acid content in purified product increased from 27.80% to 45.01% (w/w), the recovery rate being 90.23% (w/w). It is necessary to detect sodium chloride contents before the mixture containing chondroitin sulfate and sodium chloride is quantitatively analyzed. Glucuronic acid content can be determined by carbazole method. The results showed that sodium chloride enhanced the color reaction. The contents of glucuronic acid or chondroitin sulfate could be calculated according to relative standard equation. Paper chromatography was applied to separate and qualitatively detect chondroitin sulfate, but many problems wait for further researches. The extraction and purification conditions for chondroitin sulfate were established. The results can offer important references on preparation and effective utilization of chondroitin sulfate.