Abstract: We aim to establish an extraction process of hyaluronic acid（HA）from the tissues of plateau zokor（Myospalax baileyi）. One-factor experiments were used to determine the optimal conditions of crude extraction,enzymolysis,and edulcoration process,and response surface method was applied to further optimize the crude extraction and enzymolysis process. The molecular structure of the extracted HA was determined by infrared spectrophotometry,the content of glucuronic acid by the Bitter-Muir method,and the molecular weight by the method of viscosity and size exclusion chromatography. As results,the optimal conditions of crude extraction was: liquid/material ratio 4 mL/g（water/tissues,V/W）,extraction temperature 26℃,and extraction time 1.6 h. The optimal enzymolysis process was: temperature 37℃,pH 8.7,and 0.7% added enzyme（1:250 trypsasy/tissue,W/W）. The optimal edulcoration process was: 20% chlorobenzene（chlorobenzene/HA solution,V/V）,95% alcohol precipitation ratio in 3 times volume,7% activated carbon（activated carbon/HA solution,W/V）to do edulcoration,and dialysis for 3 h. Under above optimal conditions,144 ± 3.61 mg HA powder was obtained from 500 g tissues of plateau zokor,and the average recovery rate was 72.73%. Infrared spectrum displayed the same absorption peak of HA by standard samples from Sigma. The mass fraction of glucuronic acid was 45.60%,and the protein content was 0.11%. The molecular weight of hyaluronic acid reached 3×106 Da. Conclusively,the HA from plateau zokor’s tissues by this extraction method is of good recovery rate and high purity,and HA in the tissues of plateau zokor is of high molecular weight and high content.

Key words: plateau zokor, hyaluronic acid, extraction process, characterization methods