2,3-Diamino acid modifying 3S-tetrahydroisoquinoline-3-carboxylic acids: Leading to a class of novel agents with highly unfolded conformation, selective in vitro anti-platelet aggregation and potent in vivo anti-thrombotic activity Original Research Artic

In the preparation of anti-thrombotic agents the 2- and 3-positions of 3S-tetra-hydroisoquinoline-3-carboxylic acid (THIQA) were simultaneously modified with amino acids to form 20 novel N-(3S-N-aminoacyl-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)amino acids (8a–t). On an in vitro platelet aggregation model 8a–t selectively inhibit ADP-induced platelet aggregation and their IC50 values are leas than 3.5 nM. On an extracorporeal circulation of arterioveinos cannula model of rats both orally and intraveously effective doses of 8a–t are less than 30 nmol/kg. Cerius2 based stereoview of explores 8a–t having highly unfolded conformation. 3D QSAR analysis gives the importance of the unfolded conformation to high in vitro anti-platelet aggregation and in vivo anti-thrombotic potency rational understanding.