Patent ID: 9078916
Filing Date: 2015-07-14
Classification: A61K,A61P,C08B

Abstract:
1. A method of preparing a copolymer of sodium carboxymethyl cellulose with a degree of substitution of 0.35 to 0.80 and gossypol, wherein the copolymer is of Formula (1): wherein a:b:c is 1:(3-6):(5-7); n is 40-50; and the copolymer has a molecular weight of 120,000-130,000; comprising (a) reacting an aqueous solution of sodium carboxymethyl cellulose with a degree of substitution of 0.35 to 0.80 with an aqueous solution of periodic acid or sodium to form a reaction mixture, wherein the reaction mixture reaches a pH value of 3.0 to 4.5 when carbon dioxide is passed through the reaction mixture; then incubating the reaction mixture at 5-8° C. in a light-protected place for from 15 to 18 hours; (b) isolating crude dialdehyde carboxymethyl cellulose from the reaction mixture of step (a); (c) treating the crude dialdehyde carboxymethyl cellulose with gossypol or gossypol-acetic acid to form another reaction mixture; (d) neutralizing the reaction mixture of step (c) with an aqueous alkaline solution; and (e) isolating the copolymer by precipitation with an organic solvent.