Derivatives of partially desulphated glycosaminoglycans endowed with antiangiogenic activity and devoid of anticoagulating effect

Abstract

Partially desulphated glycosaminoglycan derivatives are described, particularly heparin, and more particularly formula (I) compounds, where the U, R and R 1 groups have the meanings indicated in the description. The glycosaminoglycan derivatives are endowed with antiangiogenic activity and are devoid of anticoagulant activity.

1 . A 2-O-desulphated glycosaminoglycan derivative, particularly a 2-O-desulphated heparin, with a 2-O-desulphation degree not greater than 60% of the total uronic units.  
     
     
         2 . A derivative according to  claim 1 , which is a heparin-like glycosaminoglycan.  
     
     
         3 . A derivative according to  claim 1 , which is a modified heparin, containing glycosamine residues with different degrees of N-desulphation and optional subsequent total or partial N-acetylation.  
     
     
         4 . A derivative according to  claim 1 , which has the following formula (I):  
       
         
           
           
               
               
           
         
       
       where the U ring can have the following meanings:  
       
         
           
           
               
               
           
         
         X and X′, which can be the same or different, are an aldehyde group or the —CH 2 —D group, where D is hydroxy or an amino acid, a peptide or a residue of a carbohydrate or oligosaccharide;  
         R and R 1 , which can be the same or different, are an SO 3  or acetyl residue;  
         n and m, which can be the same or different, may vary from 1 to 40; the sum of n+m ranges from 6 to 40; the m:n ratio ranges from 10:2 to 1:1, the symbol   indicates that units marked m and n are statistically distributed along the polysaccharide chain and are not necessarily in sequence.  
       
     
     
         5 . A derivative according to  claim 4 , which is partially 2-O-desulphated heparin with a molecular weight (MW) of 11200, a polydispersion index D of 1.3, a desulphation degree of 1.99 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids compared to total uronic acids approximately 50%.  
     
     
         6 . A derivative according to  claim 4 , which is partially 2-O-desulphated heparin with a molecular weight (MW) of 12900 D, a polydispersion index D of 1.5, a desulphation degree of 2.05 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids compared to total uronic acids: 5% epoxide groups, 29% oxidated and reduced uronic residues.  
     
     
         7 . A derivative according to  claim 4 , which is partially 2-O-desulphated heparin with a molecular weight (MW) of 11000 D, a polydispersion index D of 1.5, a desulphation degree of 1.93 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids compared to total uronic acids: 5% epoxide groups, 29% oxidated and reduced uronic residues.  
     
     
         8 . A derivative according to  claim 4 , which is partially 2-O-desulphated heparin with a molecular weight (MW) of 9200 D, a polydispersion index D of 1.5, percentage of modified uronic acids compared to total uronic acids: 11% epoxide groups, 27.5% oxidated and reduced uronic residues.  
     
     
         9 . Process for the preparation of the derivatives according to  claim 1 , comprising the following steps: 
 (a) basic treatment at a temperature ranging from ambient temperature to approximately 100° C., preferably from 50 to 70° C., and even more preferably at approximately 65° C., which leads to the elimination of a controlled percentage of sulphate groups in position 2 of the iduronic acid and to the formation of epoxide groups; and, if desired    (b) opening of said epoxide ring at approximately pH 7, at a temperature ranging from approximately 50° C. to approximately 100° C., preferably at approximately 70° C. to yield residues of galacturonic acid; or, alternatively    (c) opening of said epoxide ring at a temperature ranging from approximately 0° C. to approximately 30° C., preferably at approximately 25° C. to yield residues of iduronic acid; and, if desired    (d) oxidation of the diols with sodium periodate, to yield the opening of the glycoside ring and the formation of two aldehyde groups per modified residue;    (e) reduction of said aldehyde groups to primary alcohol and, if desired, transformation of the D group to a group other than hydroxy, as envisaged in the different meanings;    (f) optional acid hydrolysis to obtain oligosaccharides corresponding to the regular sequences, or alternatively    (g) partial enzymatic hydrolysis with an enzyme selected from the group consisting of lyase, heparinase, heparitinase, or equivalent of products obtained in step e) to yield oligosaccharides, preferably tetra- or octa-saccharides, with the non-reducing terminal residue consisting of unsaturated iduronic acid, the reducing residue consisting of an N-sulphoglucosamine and containing at least one residue of open iduronic acid; or, alternatively    (h) the compound obtained in step a), or the product obtained in step b) is treated by partial enzyme hydrolysis; and, if desired    (i) subjection of the products obtained in one of steps a), b) and e) to partial 6-O-desulphation; or, alternatively,    (j) subjection of the starting heparin partially or totally 6 desulphated to steps a), b) and e).    
     
     
         10 . Partially 2-O-desulphated heparin, obtainable by the process according to  claim 9 , where step a) is conducted for 45 min at 60° C. and step b) at 70° C. at pH 7, and with a molecular weight (MW) of 11200, a polydispersion index D of 1.3, a desulphation degree of 1.99 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids about 50% compared to total uronic acids.  
     
     
         11 . Partially 2-O-desulphated heparin, obtainable by the process according to  claim 9 , where step a) is conducted for 15 min at 60° C. and step b) at 70° C. at pH 7, and with a molecular weight (MW) of 12900 D, a polydispersion index D of 1.5, a desulphation degree of 2.05 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids compared to total uronic acids: 5% epoxide groups, 29% oxidated and reduced uronic residues.  
     
     
         12 . Partially 2-O-desulphated heparin, obtainable by the process according to  claim 9 , where step a) is conducted for 30 min at 60° C. and step b) at 70° C. at pH 7, and with a molecular weight (MW) of 11000 D, a polydispersion index D of 1.5, a desulphation degree of 1.80 (expressed as SO 3 —:COO— molar ratio), percentage of modified uronic acids compared to total uronic acids: 5% epoxide groups, 29% oxidated and reduced uronic residues.  
     
     
         13 . Partially 2-O-desulphated heparin, obtainable by the process according to  claim 9 , where step a) is conducted for 60 min at 60° C. and step b) at 70° C. at pH 7, and with a molecular weight (MW) of 9200 D, a polydispersion index D of 1.5, percentage of modified uronic acids compared to total uronic acids: 11% epoxide groups, 27.5% oxidated and reduced uronic residues.  
     
     
         14 . Mixtures of oligosaccharides with antiangiogenic activity obtainable from the acid degradation of compounds according to  claim 4 .  
     
     
         15 . Mixtures of oligosaccharides with antiangiogenic activity obtainable from step f) of the process according to  claim 9 .  
     
     
         16 . Mixtures of oligosaccharides with antiangiogenic activity obtainable from step g) of the process according to  claim 9 .  
     
     
         17 . Mixtures of oligosaccharides with antiangiogenic activity obtainable from step h) of the process according to  claim 9 .  
     
     
         18 . Mixtures of oligosaccharides with antiangiogenic activity obtainable from step i) of the process according to  claim 9 .  
     
     
         19 . Pharmaceutical compositions containing at least one compound according to  claim 1  as an active ingredient in admixture with pharmaceutically acceptable vehicles and excipients.  
     
     
         20 . Use of compounds according to  claim 1  as medicaments.  
     
     
         21 . Use of compounds according to  claim 1 , for the preparation of a medicament with antiangiogenic activity.  
     
     
         22 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of pathological states due to abnormal angiogenesis.  
     
     
         23 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of tumours, optionally associated with metastases.  
     
     
         24 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of tumour metastases.  
     
     
         25 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of diabetic retinopathy.  
     
     
         26 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of retrolenticular fibroplasia.  
     
     
         27 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of psoriasis.  
     
     
         28 . Use of compounds according to  claim 1 , for the preparation of a medicament for the treatment of restenosis after angioplasty and after coronary by-pass.