Polymer-Assisted Solution-Phase Library Synthesis and Crystal Structure of α-Ketothiazoles as Tissue Factor VIIa Inhibitors
作者:John J. Parlow、Thomas A. Dice、Rhonda M. Lachance、Thomas J. Girard、Anna M. Stevens、Roderick A. Stegeman、William C. Stallings、Ravi G. Kurumbail、Michael S. South
DOI:10.1021/jm030130t
日期:2003.9.1
A solution-phase synthesis of an alpha-ketothiazole library of the general form D-Phe-L-AA-Arg-alpha-ketothiazole is described. The five-step synthesis is accomplished using a combination of polymeric reagents and polymer-assisted solution-phase purification concepts, including reactant-sequestering resins, reagent-sequestering resins, and tagged reagents. The multistep synthesis affords desired alpha-ketothiazole products in excellent purities and yields. A variety of L-amino acid inputs were used to probe the S-2 pocket of tissue Factor VIIa enzyme to influence both potency and selectivity. An X-ray crystal structure of compound 10k bound to the TF/ VIIa complex was obtained that explains the observed selectivity. The alpha-ketothiazoles were found to be potent, reversible-covalent inhibitors of tissue Factor VIIa, with some analogues demonstrating selectivity over thrombin.