Menetelmä uusien hepariinijohdannaisten valmistamiseksi

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 ueight 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 peculiar chemical-physical characteristics, in particular they present a C-NMR spectrum different from that of the starting haparins especially in the zone comprised between 102 and 92 p.p.m., with the presence of a characteristic signal at 101.3 p.p.m., a specific rotatory power at 546 nm comprised betueen about +15 DEG and about +40 DEG in aqueous solution, a sulfur content comprised between about 6% and about 9%, a sulfate/carboxyls ratio comprised between about 1.20 and about 1.70 and a content of free amino groups comprised between about 0.4% and about 2.1%. Said heparinic derivatives can be useful in the treatment of the nephrolithiases.