Design, synthesis, and biological evaluation of potent and selective amidino bicyclic factor Xa inhibitors

Thrombotic diseases are a major cause of death and morbidity. Factor Xa (fXa) plays a vital role in the regulation of normal homeostasis and abnormal intravascular thrombus development in the blood coagulation cascade. A novel series of fXa inhibitors incorporating an amidino 6,5-fused bicyclic moiety at the P1 position has been designed and synthesized based on molecular modeling studies. Structure-activity relationship (SAR) studies have led to selective subnanomolar fXa inhibitors. The most potent fXa inhibitor in this series (72, SE170) has a potent inhibition constant (K(i) = 0.3 nM), is 350-fold selective for fXa over trypsin, and also shows good in vivo efficacy in a rabbit arterio-venous thrombosis model (ID(50) = 0.14 micromol/kg/h). An X-ray crystal structure of 72 complexed to bovine trypsin was completed, and a binding mode of 72 with fXa has been proposed based on modeling with human des-Gla-fXa.

Design and synthesis of potent and selective 5,6-fused heterocyclic thrombin inhibitors

Thrombin, a serine protease, plays a central role in the initiation of thrombotic events. We report the design, synthesis, and antithrombotic efficacy of XU817 (7), a nonpeptide 5-(amidino) indole thrombin inhibitor. Utilizing the co-crystal structure of XU817 bound in the active site of thrombin we were able to synthesize analogs with enhanced thrombin affinity.

Moiré gauging of in-plane displacement using double aperture imaging

An easily implemented method of measuring in-plane surface displacement by photographing an object through two laterally displaced apertures is described and the experimental results are presented. The displacement is displayed as a pattern of moiré fringes over the image. No previously constructed grids or rulings are required as in normal moiré devices. The method is noncontacting and requires no special surface preparation. The sensitivity is easily adjusted and is shown to be equivalent to that obtained using double-exposure holography or speckle pattern interferometry techniques. The method has potential application in mechanically unstable environments or where the conditions are such that grids or strain gauges cannot be attached to the object.