Process for preparing epoxy-heparides, the products obtained and pharmaceutical compositions containing them

摘要

There is provided a process for preparing epoxy-heparide polysaccharides of formula (I): <IMAGE> (I) wherein A is a pyran ring with substituents 1 and 4 in the axial position and 5 in the equatorial position, and R and R' are hexosamines which constitute a polysaccharide chain bonded to said ring A by a glucoside, and one of R and R' is H when the ring A is in the terminal position of said polysaccharide chains, and said heparide has a COCH3 to COOH ratio of 0.5, said process comprising a) N-desulfation of heparin to obtain the corresponding heparamine; b) acetylation of the heparamine of step (a) to obtain the corresponding heparide; c) epoxidation of the heparide of step (b) by treating the heparide with hydrogen peroxide in an alkaline reaction medium at pH 12-14; and d) cooling the solution obtained in step (c) to a temperature of between 15 DEG and 25 DEG C. and adjusting the pH to between 5.8 and 6.0.