Process for the depolymerization of heparin for obtaining heparin with a low molecular weight and having an antithrombotic activity

摘要

Depolarised heparin having low mol. wt. is obtd. by treating a quaternary ammonium salt of heparin with a quaternary ammonium hydroxide in a non-hydroxylated solvent, and isolating the prod. as a sodium, calcium or magnesium salt. The heparin may be of various origins (cattle, pigs, sheep) and this is treated with the ammonium hydroxide at 10-60 deg.C. The solvent used may be dichloromethane, formamide, or dimethylformamide, or any other solvent free from hydroxyl gps.. The ammonium hydroxide used is pref. benzyl trimethyl ammonium hydroxide (Triton B; RTM). If desired the product may undergo a mild redn., e.g. with sodium or potassium borohydride, to stabilise terminal gps.. The final prod. has a mol. wt. between 2500 and 6000 daltons, and may be purified by fractional precipitation, chromatography, or ultrafiltration.