Compositions of partially deacetylated chitin derivatives

摘要

Disclosed herein is a method for recovering highly pure and fully soluble partially deacetylated chitin polymers with a degree of deacetylation (DD) between 30-60%, the method comprising the steps of: i) Neutralisation of the partially deacetylated chitin; ii) dissolving the partially deacetylated chitin in acidic solution; iii) removing undissolved particles through sequential filtering steps; iv) adjusting the solution to pH above 8; v) precipitating the fully dissolved and purified partially deacetylated chitin into a precipitate through elevated temperature and addition of salt, wherein the precipitate is recovered and washed after precipitation through sieving or by centrifugation and wherein the temperature of the washing water and the precipitate is above 400C. Also disclosed is a composition comprising therapeutically active chitooligomers of N-acetyl glucosamine (A) and glucosamine (D), wherein the composition comprises hetero-chitooligomers which fulfil the following criteria: i) said oligomers having a chain length in the range of 5-20 monomer residues; ii) each oligomer chain can have two N-acetyl glucosamine residues (AA) on either or both ends of the oligomer chain; iii) the remaining internal part of the oligomer having a maximum amount of A residues; iv) the sequence of said internal chain being such that an N-acetyl glucosamine residue (A) is not adjacent to another N-acetyl glucosamine residue (such as AA).