Synthesis of heparin-like antithrombotics having perphosphorylated thrombin binding domains

The synthesis of three heparin analogues (i.e. compounds VI-VIII) having perphosphorylated thrombin binding domains (TBDs) is reported. These compounds were tested in vitro for their antithrombin III (ATIII)-mediated anti-Xa and antithrombin activities. Conjugates VI and VIII show a remarkable increase in antithrombin activity compared to the structurally related conjugates with persulfated TBDs (i.e. compounds IV and V), whereas compound VII displays a diminished activity.