Extending SAR of bile acids as FXR ligands: discovery of 23-N-(carbocinnamyloxy)-3α,7α-dihydroxy-6α-ethyl-24-nor-5β-cholan-23-amine.

Within our efforts in the discovery of novel potent and selective ligands for the FXR receptor, 23-N-(carbocinnamyloxy)-3α,7α-dihydroxy-6α-ethyl-24-nor-5β-cholan-23-amine was synthesized and evaluated for its ability to activate and modulate the biological response of the receptor. Alphascreen and RT-PCR revealed that the 6α-ethyl-24-norcholanyl-23-amine derivate behaves as full FXR agonist endowed with high binding affinity and efficacy, representing a promising lead candidate for further optimization. In addition, docking studies provide new insights into the molecular basis governing the partial and full agonist activity at FXR.