Abstract: New heparinic derivatives having anticalculous activity, devoid of the anticoagulant and antithrombotic activity characteristic of the heparins, obtained by treating commercial or purified or low molecular weight heparins in a basic medium, optionally in the presence of alkali metal salts and of a reducing agent. The heparinic derivatives obtained through this treatment show significant chemical-physical characteristics, in particular they present a .sup.13 C-NMR spectrum different from that of the starting heparins especially in the zone between 102 and 92 p.p.m. with a characteristic signal at 101.3 p.p.m., a specific rotatory power at 546 nm between about +15.degree. and about +40.degree. in aqueous solution, a sulfur content between about 6% and about 9%, a sulfate/carboxyl ratio between about 1.20 and about 1.70 and a content of free amino groups between about 0.4% and about 2.1%. These heparin derivatives can be useful in the treatment of the nephrolithiases.

Abstract: New heparin derivatives having antithrombotic activity, also endowed with reduced hemorrhagic and anticoagulant activity, obtained by treating in a basic medium heparins of various origin, optionally in the presence of alkali metal salts and of a reducing agent.The heparin derivatives obtained through this treatment show peculiar chimico-physical characteristics, like new signals at about 53 and 54 p.p.m. in the .sup.13 C-NMR spectrum and an increase of the specific rotatory power, compared to that of the starting heparins, to values between +50.degree. to +90.degree..Said structural modifications produce an improvement of the biological properties of the heparin, substantially keeping the antithrombotic activity while diminishing the hemorrhagic effect in vivo and the anticoagulant activity in vitro.