A novel factor Xa inhibitor: structure-activity relationships and selectivity between factor Xa and thrombin

Area of Science:

• Medicinal Chemistry
• Biochemistry
• Structural Biology

Background:

• Factor Xa (FXa) is a critical enzyme in the coagulation cascade, making it a therapeutic target for anticoagulation.
• Developing selective FXa inhibitors is crucial to minimize off-target effects, such as inhibiting thrombin.

Purpose of the Study:

• To investigate novel 3-amidinoaryl-2-[4-[[(3S)-3-pyrrolidinyl]oxy]phenyl] propanoic acid derivatives as potential Factor Xa inhibitors.
• To elucidate the structure-activity relationships (SAR) and selectivity profile of these compounds against Factor Xa and thrombin.

Main Methods:

• Synthesis and evaluation of a series of novel propanoic acid derivatives.
• Construction of molecular models of Factor Xa-inhibitor complexes using X-ray crystallographic data of a trypsin-inhibitor complex.
• Analysis of binding modes within the enzyme's active site, particularly the S1 pocket.

Main Results:

• The investigated compounds demonstrated potent inhibitory activity against Factor Xa.
• High selectivity for Factor Xa over thrombin was observed for the developed inhibitors.
• Molecular modeling indicated that the binding mode within the S1 pocket correlated with observed SAR.

Conclusions:

• The novel propanoic acid derivatives represent promising candidates for Factor Xa inhibitor development.
• The structural difference between Gln192 in Factor Xa and Glu192 in thrombin is a key determinant for inhibitor selectivity.
• Understanding these structural-enzyme interactions facilitates the rational design of more effective anticoagulants.