Separation And Purification Of Hyaluronic Acid

Hyaluronic acid (HA), a high molecular weight mucopolysaccharide, was discovered by Meyer and Palmer in1934in the vitreous humor of cattle eyes. HA is a linear uncharged glycosaminoglycan, consisting of alternating sequences of (3-(1-4)-glucoronic acid and β-(1-3)-N-acetyglucosaminemoie-ties. Because it has the property that high viscosity and good capacity of water-holding, It can be widely used for cosmetic, health food and medicine.There are two ways to prepare HA:extraction from animal’s tissue and fermentation by streptococcus. In this paper, A method was developed to separate and purify hyaluronic acid (HA) from fermentation broth. The concretely content are as follows.1. The methods to separate HA from broth were researched. The method with alcohol were optimized to separate HA from fermentation broth. The optimal conditions was adding2L alcohol per litre broth.The method with CTAB were developed. The optimal conditions of HA recovery with CTAB were determined. The fermentation broth was diluted by distilled water, and the volume ratio of the broth to water is1:3.5(v/v). The pH of the culture diluted was adjusted to6.5.Then,10%(w/v) CTAB was added into the culture diluted to finanal concentration12%(v/v). The yield of HA was up to97.0%. Comparing the two methods of separating HA from fermentation broth with CTAB and with alcohol, the purity and the yield of the latter method was better than the former one. However, the cost of the latter method was lower33.3%than the former one. So the method with alcohol to precipitate HA from broth was more sutable in industry.2. The method to purify HA was developed. Crude HA was dissolved in distilled water and reached its concentration of20g/L. Cilite as sorbent was added into the HA solution. pH of the solution was adjusted between4.6-4.8. Then, the solution was filtrated with cilite, filter B-1and ultrafiltration membrane. Finally the HA solution was crystallized by ethanol.thus, farinose HA containing glucuronic acid40%～45.2%was prepared, and the yield of HA was82.7-95.6%.3. This method was successfully applied to the industry in Xinjiang Dushanzi Petrochemical Corporation. The relative molecular weight of factory product was up to1.1-2.06X106Da. The factory product contained40-47.3%glucuronic acid and only0.01-0.1%protein. The yield of HA reach to≥81.7%in the factory.4. The HA product produced by the above-mentioned method was compared with HA from Furuida Company and Dongchen Company, including glucuronic acid content, protein content, Na+content, photic ratio, microcosmic structure and Infrared absorption spectrum. The result shows that Dushanzi HA can meet with the demand of cosmetic.