Polysaccharides with antithrombotic activity, including a covalent bond and an amino chain

1. A synthetic polysaccharide with antithrombotic activity, corresponding to the formula:

wherein:

the wavy line denotes a bond located either below or above the plane of the pyranose ring, and

the formula:

denotes a polysaccharide containing n identical or different monosaccharide units, said polysaccharide being bonded via its anomeric carbon to Pe, and

the formula:

is a diagrammatic representation of a monosaccharide unit with a pyranose structure, chosen from hexoses, pentoses and the corresponding deoxy sugars, this unit being bonded via its anomeric carbon to another monosaccharide unit, and the hydroxyl groups of this unit being substituted with groups R 1 , which may be identical or different, R 1 being as defined below, and

Pe represents a pentasaccharide having the structure:

wherein

h is equal to 1 or 2, and

n is an integer and can take any value from 0 to 25, and

R 1 represents an —NH—CO—(CH 2 ) 5 —NH 2 group, a (C 1 -C 6 )alkoxy group or an —OSO 3 − group; and

R 2 represents an —NH—CO—(CH 2 ) 5 —NH 2 group, a (C 1 -C 6 )alkoxy group or an —OSO 3 − group; and

R 3 represents an —NH—CO—(CH 2 ) 5 —NH 2 group or a (C 1 -C 6 )alkoxy group; and

R 4 represents an —NH—CO(CH 2 ) 5 —NH 2 group, a (C 1 -C 6 )alkoxy group or an —OSO 3 − group or else R 4 constitutes an —O—CH 2 bridge, the —CH 2 — group being bonded to the carbon atom bearing the carboxylic function on the same ring; and

wherein at least one of the substituents R 1 , R 2 , R 3 or R 4 represents an —NH—CO—(CH 2 ) 5 —NH 2 group; and wherein

W represents an oxygen atom or a methylene group, and pharmaceutically acceptable salts thereof.

2. The polysaccharide according to claim 1 , corresponding to formula (I.1):

wherein:

the formula:

denotes a polysaccharide Po, bonded via its anomeric carbon to Pe as defined in claim 1 , and

the formula:

is as defined in claim 1 , wherein

the R 1 groups are as defined in claim 1 and, for the same monosaccharide, may be identical or different, and

the monosaccharide contained in [ ] m is repeated m times, the monosaccharide contained in [ ] t is repeated t times, the monosaccharide contained in [ ] p is repeated p times, and wherein

m is an integer ranging from 1 to 5, t is an integer ranging from 0 to 24 and p is an integer ranging from 0 to 24, wherein

1 ≦m+t+p≦ 25,

and pharmaceutically acceptable salts thereof.

3. The polysaccharide according to claim 2 , wherein just one of the substituents R 1 , R 2 , R 3 or R 4 represents an —NH—CO—(CH 2 ) 5 —NH 2 group, and pharmaceutically acceptable salts thereof.

4. The polysaccharide according to claim 1 wherein said polysaccharide is of formula (I.2):

wherein:

T represents an —NH—CO—(CH 2 ) 5 —NH 2 group, and

Pe represents a pentasaccharide having the structure:

wherein in which:

R 1 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, and

R 2 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, and

R 3 represents a (C 1 -C 6 )alkoxy group, and

R 4 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, or else R 4 constitutes an —O—CH 2 bridge, the —CH 2 — group being bonded to the carbon atom bearing the carboxylic function on the same ring, and wherein

W represents an oxygen atom or a methylene group,

and pharmaceutically acceptable salts thereof.

5. The polysaccharide according to claim 1 , wherein said polysaccharide is a pentasaccharide of formula (I.3):

wherein R 1 , R 2 , R 3 , R 4 and W are as defined in claim 1 , and pharmaceutically acceptable salts thereof.

6. The polysaccharide according to claim 5 , wherein said pentasaccharide comprises just one of the substituents R 1 , R 2 , R 3 or R 4 represents an —NH—CO—(CH 2 ) 5 —NH 2 group, and pharmaceutically acceptable salts thereof.

7. The polysaccharide according to claim 5 wherein said pentasaccharide corresponds to formula (I.4):

wherein:

T represents an —NH—CO—(CH 2 ) 5 —NH 2 group, and

R 1 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, and

R 2 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, and

R 3 represents a (C 1 -C 6 )alkoxy group, and

R 4 represents a (C 1 -C 6 )alkoxy group or an —OSO 3 − group, or else R 4 constitutes an —O—CH 2 bridge, the —CH 2 — group being bonded to the carbon atom bearing the carboxylic function on the same ring, and wherein

W represents an oxygen atom or a methylene group,

and pharmaceutically acceptable salts thereof.

8. The polysaccharide according to claim 1 , wherein the polysaccharide is methyl (2-[N-(6-aminohexanoyl)]-2-deoxy-3,4-di-O-methyl-6-O-sulfonato-α-D-glucopyranosyl)-(1→4)-(2,3-di-O-methyl-β-D-glucopyranosyluronic acid)-(1→4)-(2,3,6-tri-O-sulfonato-α-D-glucopyranosyl)-(1→4)-(2,3-di-O-methyl-α-L-idopyranosyluronic acid)-(1→4)-2,3,6-tri-O-sulfonato-α-D-glucopyranoside sodium salt.

9. A pharmaceutical composition comprising, as an active ingredient, the polysaccharide according to claim 1 , and one or more suitable inert excipients.

10. A method of treating a thromboembolic disorder in a patient in need thereof comprising administering to said patient a therapeutically effective amount of the pharmaceutical composition of claim 9 .