Preserving the original heparin structure of a novel low molecular weight heparin by gamma-irradiation

Several preparations of low molecular weight heparins (LMWHs) obtained by p hysical depolymerisation (irradiation with gamma -rays) of pig mucosal hepa rin have been characterised by mono- and two-dimensional NMR spectroscopy. Integration of typical H-1- and C-13-NMR signals provided a useful quantifi cation of their sulfation pattern. The availability of the corresponding pa rent heparins showed that the original structure (including that of the act ive site for antithrombin, as also confirmed by affinity chromatography) ha d not been significantly modified by the depolymerisation procedure. This p rocess Involves only a slight decrease of undersulfated sequences. A peculi arity of gamma -LMWH is the absence of the 'linkage region, commonly presen t In unmodified heparins and most LMWHs.