US 12,435,162 B2
Preparation method for acetylated sodium hyaluronate
Lei Liu, Shandong (CN); Chunxi Wang, Shandong (CN); Qing Li, Shandong (CN); Chuanli Kang, Shandong (CN); Jingjing Sun, Shandong (CN); Liwei Tang, Shandong (CN); Qiang Liu, Shandong (CN); Shaojie Lian, Shandong (CN); Meixia Zhang, Shandong (CN); Mengyi Zhang, Shandong (CN); Ququan Li, Shandong (CN); and Shuai Du, Shandong (CN)
Assigned to SHANDONG FOCUSFREDA BIOTECH CO., LTD, Shandong (CN)
Appl. No. 17/918,906
Filed by SHANDONG FOCUSFREDA BIOTECH CO., LTD, Shandong (CN)
PCT Filed Feb. 28, 2022, PCT No. PCT/CN2022/078460
§ 371(c)(1), (2) Date Oct. 14, 2022,
PCT Pub. No. WO2022/222607, PCT Pub. Date Oct. 27, 2022.
Claims priority of application No. 202110427110.6 (CN), filed on Apr. 21, 2021.
Prior Publication US 2023/0295351 A1, Sep. 21, 2023
Int. Cl. C08B 37/08 (2006.01)
CPC C08B 37/0072 (2013.01) 6 Claims
 
1. A preparation method for acetylated sodium hyaluronate, wherein the preparation method comprises the following steps:
in the protective atmosphere of inert gas, subjecting a hyaluronate and an acetic anhydride to a catalytic reaction in an organic solvent with a catalyst added, adding a water absorbent during the reaction, obtaining a reaction liquid, subjecting a reaction liquid to post treatment, separation, purification, and drying to obtain a product;
wherein reaction of the hyaluronate and the acetic anhydride is as follows: dissolving the hyaluronate in the organic solvent until a homogeneous phase is formed, adding the water absorbent, decreasing a temperature of the reaction system to 10° C.-−5° C., dropwise adding the acetic anhydride to the reaction system, then dropwise adding a DMAP-toluene solution to the reaction system, after reacting for a certain time, heating the reaction system to 40° C.-70° C. for reacting for a certain time;
wherein a mass ratio of the hyaluronate to the acetic anhydride ranges from 1:1 to 1:5, an average molecular weight of the hyaluronate ranges from 5 KDa to 5000 KDa;
wherein after the catalytic reaction is finished, the post treatment to the reaction liquid is as follows: adding water to the reaction liquid to remove the remaining acetic anhydride, and then filtering the reaction liquid to remove the water absorbent.