Discovery and Optimization of 1,3,4-Trisubstituted-pyrazolone Derivatives as Novel, Potent, and Nonsteroidal Farnesoid X Receptor (FXR) Selective Antagonists

LBVS of 12480 in-house compounds, followed by HTRF assay, resulted in one nonsteroidal compound (11) with antagonistic activity against FXR (69.01 ± 11.75 μM). On the basis of 11, 26 new derivatives (12a-z) were designed and synthesized accordingly. Five derivatives (12f-g, 12p, 12u, and 12y) showed better antagonistic activities against FXR than compound 11. Remarkably, the most potent derivative, 12u (8.96 ± 3.62 μM), showed antagonistic capability approximately 10 times and 8-fold higher than that of the control (GS) and the starting compound 11, respectively. 12u was further confirmed to have high binding affinity with FXRαLBD, FXR specificity over six other nuclear receptors, and potent antagonistic activity against FXR in two cell testing platforms. 12u strongly suppressed the regulating effects of CDCA on FXR target genes. The therapeutic potential of 12u was identified by lowering the contents of triglyceride and cholesterol in human hepatoma HepG2 cells and in the cholesterol-fed C57BL/6 mices.