Partially depolymerized heparin products having particular analyzable reducing end groups, a process for their preparation and their use as anticoagulants and antithrombotics.
Method for obtaining biologically active mucopolysaccharides by controlled depolymerization of heparin, wherein the quantity of products generating nitrous acid is selected so that those products are totally consumed when the desired depolymerization degree is reached.
Heparin fractions which are a mixture of oligosaccharides containing 6-12 monosaccharides are described. The oligosaccharides contain reducing end groups composed of iduronic acid 2-sulfate or glucosamine N, 6-disulfate. The end group monosaccharides contain the reducing anomeric carbons. The SO.sub.3.sup.- /COO.sup.- ratio is essentially the same as in heparin. The method of preparation is a depolymerization initiated by free radicals. One fraction is a heparin fragment with a molecular weight (MWw) of 2,100 daltons (+10%). The compound contains 6-8 monosaccharides, has the same SO.sub.3.sup.- /COO.sup.- ratio as the parent heparin and has platelet anti-aggregating activity, arterial and venous antithrombotic action, fibrinolytic and antiatherosclerotic activity. It exhibits poor anti factor Xa activity and no anticoagulant action.
Pharmaceutical compositions are described which have antithrombotic activity suitable for the prevention and for the therapy of cardiac infarcts, cerebral infarcts and venous thrombosis. They contain as the active component a fraction of heparin which has been modified by nitrogen desulfatation and succinylation, which fraction contains less than 10% of the N-sulfate groups of the heparin starting material and more than 0.6 succinyl radicals per disaccharide unit. The method of treatment is described.
A new anti-thromboticum based on a mixture of oligo- and polysaccharides is provided. The invention also relates to methods for preparation thereof and to pharmaceutical compositions including the said anti-thromboticum. The new product is of natural origin and can be obtained from mammal tissue, particularly intestinal mucous. The product is useful because of its high "benefit/risk" ratio (i.e. the ratio between the anti-thrombotic activity and the haemorrhagic activity).
Novel oligosaccharide fractions with valuable pharmacological properties are obtained from heparin. They have the same structural characteristics of heparin. The heparin fraction consists of oligosaccharides which contain end groups consisting of iduronic acid 2-sulfate, or glucosamine N, 6-disulfate. Further the oligosaccharides contain and monosaccharide endowed with reducing anomeric carbon, and are constituted by multiples of monosaccharide units.
