Method for deacetylation of biopolymers

Patent metadata

Field	Value
Publication number	US-2019016830-A1
Application number	US-201616066746-A
Country	US
Kind code	A1
Filing date	Dec 28, 2016
Priority date	Dec 29, 2015
Publication date	Jan 17, 2019
Grant date	—

Abstract

A method for at least partial deacetylation of a biopolymer comprising acetyl groups, including: a1) providing a biopolymer including acetyl groups; a2) reacting the biopolymer including acetyl groups with hydroxylamine (NH 2 OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated biopolymer; and a3) recovering the at least partially deacetylated biopolymer.

First claim

1 . A method for at least partial deacetylation of a glycosaminoglycan comprising acetyl groups, comprising:
a1) providing a glycosaminoglycan comprising acetyl groups; a2) reacting the glycosaminoglycan comprising acetyl groups with hydroxylamine (NH 2 OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated glycosaminoglycan; and a3) recovering the at least partially deacetylated glycosaminoglycan.

2 . The method according to claim 1 , wherein the glycosaminoglycan selected from the group consisting of hyaluronic acid, chondroitin and chondroitin sulfate, and mixtures thereof.

3 . The method according to claim 1 , wherein the weight average molecular weight of the recovered at least partially deacetylated glycosaminoglycan is at least 10% of the weight average molecular weight of the glycosaminoglycan comprising acetyl groups in step a1).

4 . The method according to claim 1 , wherein the glycosaminoglycan comprising acetyl groups in step a1) has a degree of acetylation in the range of 98-100%.

5 . The method according to claim 1 , wherein the recovered at least partially deacetylated glycosaminoglycan has a degree of acetylation at least 1% less than that of the glycosaminoglycan comprising acetyl groups in step a1).

6 . The method according to claim 1 , wherein step a2) comprises reacting the glycosaminoglycan comprising acetyl groups with the hydroxylamine or salt thereof at a temperature of 100° C. or less.

7 . (canceled)

8 . The method according to claim 1 , wherein step a2) comprises reacting the glycosaminoglycan comprising acetyl groups with the hydroxylamine or salt thereof for 2-200 hours.

9 . (canceled)

10 . The method according to claim 1 , wherein step a2) comprises reacting the glycosaminoglycan comprising acetyl groups with hydroxylamine in water.

11 . The method according to claim 1 , wherein the molar concentration of hydroxylamine in step a2) is in the range of 5-20 M.

12 . The method according to claim 1 , wherein step a2) comprises reacting the glycosaminoglycan comprising acetyl groups with a hydroxylamine salt.

13 . (canceled)

14 . The method according to claim 1 , wherein the concentration of the hydroxylamine salt in step a2) is in the range of 0.1-5 M.

15 . (canceled)

16 . The method according to claim 1 , wherein the reaction in step a2) is performed at a pH value in the range of 4-12.

17 . (canceled)

18 . (canceled)

19 . (canceled)

20 . An at least partially deacetylated glycosaminoglycan obtained by the method according to claim 1 .

21 . An at least partially deacetylated glycosaminoglycan having a degree of acetylation of 99% or less, and a weight average molecular weight of 0.1 MDa or more.

22 . Use of hydroxylamine or a salt thereof to at least partially deacetylate a glycosaminoglycan comprising acetyl groups.

23 . Use according to claim 22 , wherein the glycosaminoglycan selected from the group consisting of hyaluronic acid, chondroitin and chondroitin sulfate, and mixtures thereof.

24 . A method of preparing a hydrogel product comprising crosslinked glycosaminoglycan molecules, said method comprising the steps of:
a) providing a solution comprising an at least partially deacetylated glycosaminoglycan according to claim 20 and optionally a second glycosaminoglycan; b) activating carboxyl groups on the at least partially deacetylated glycosaminoglycan and/or the optional second glycosaminoglycan with a coupling agent, to form activated glycosaminoglycans; c) crosslinking the activated glycosaminoglycans via their activated carboxyl groups using amino groups of the at least partially deacetylated glycosaminoglycans to provide glycosaminoglycans crosslinked by amide bonds.

Assignees

• Galderma Sa

Inventors

• Olsson Johan
• Harris Craig Steven

Classifications

• A61P17/00

  Drugs for dermatological disorders · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08J2305/08

  Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof · CPC title

• C08B37/0069 Primary

  Chondroitin-4-sulfate, i.e. chondroitin sulfate A; Dermatan sulfate, i.e. chondroitin sulfate B or beta-heparin; Chondroitin-6-sulfate, i.e. chondroitin sulfate C; Derivatives thereof · CPC title

• C07C2603/18

  Fluorenes; Hydrogenated fluorenes · CPC title