Discovery of (E)-3-(3-((2-Cyano-4′-dimethylaminobiphenyl-4-ylmethyl)cyclohexanecarbonylamino)-5-fluorophenyl)acrylic Acid Methyl Ester, an Intestine-Specific, FXR Partial Agonist for the Treatment of Nonalcoholic Steatohepatitis

Abstract

A series of fexaramine analogs were synthesized and evaluated to develop an intestine-selective/specific FXR partial agonist. Introduction of both a CN substituent at the C-2 in the biphenyl ring and a fluorine at the C-5 in the aniline ring in fexaramine markedly increased FXR agonistic activity. 27c showed 53 ± 3% maximum efficacy relative to GW4064 in an FXR agonist assay. A substantial amount of 27c was absorbed in the intestine after oral administration in rats, and then it was rapidly metabolized to inactive carboxylic acid 44 by serum esterases. In CDAHFD-fed mice, oral administration of 27c strongly induced multiple intestinal FXR target genes, FGF15, SHP, IBABP, and OST-α, but failed to activate SHP in the liver. 27c significantly reduced the liver fibrogenesis area, hepatic fibrosis markers, and serum level of AST. Rational optimization of fexaramine has led to the identification of an intestine-specific FXR partial agonist 27c.

Dietary Isoquercetin Reduces Hepatic Cholesterol and Triglyceride in NAFLD Mice by Modulating Bile Acid Metabolism via Intestinal FXR-FGF15 Signaling

“…51 A newly synthesized FXR agonist C27A was also reported to improve liver function of NAFLD with reduction of serum ALT. 52 Taken together, dietary isoquercetin can promote BA biosynthesis through activation of alternative pathways and inhibition of intestinal FXR, thus lowering hepatic TC and TG levels in NAFLD mice.…”

Tailoring FXR Modulators for Intestinal Specificity: Recent Progress and Insights

“…In order to assess the selectivity of compound 28, it was tested against eighteen nuclear receptors at a concentration of 100 µM using a PathHunter NHR Protein Interaction Assay. The results showed that this compound did not activate any other receptors except for the desired one [35]. This promising outcome prompted further optimization of the molecule.…”

“…Initially, the flexible biphenyl ring in Fex (20) was replaced with various tricyclic ring structures to assess the binding pocket's capability to accommodate a larger, constrained group. Unfortunately, this modification resulted in decreased activity, as observed in compounds 26 (EC 50 >10 µM, E max = 14% at 3.3 µM) and 27 (EC 50 > 10 µM, E max = 9% at 3.3 µM) (Figure 6) [35]. To examine if altering the biphenyl ring could improve hydrogen bonding with the LBD, five various substituents were added to C 2 .…”

“…However, when a cyano group was utilized, compound 28 was discovered, exhibiting enhanced potency and efficacy compared to other compounds in the series. Compound 28 demonstrated an EC 50 of 0.8 µM and an E max of 24% (Figure 6) [35]. In order to assess the selectivity of compound 28, it was tested against eighteen nuclear receptors at a concentration of 100 µM using a PathHunter NHR Protein Interaction Assay.…”

“…Binding of 41 was studied using the X-ray of Fex (20) bound with FXR (PDB ID: 1OSH). The biphenyl rings have hydrophobic interactions with Met269, Met294, Ile339, Phe340, Leu344, and Leu352 while the dimethylamine hydrophobically bonds with Leu344 [35]. Importantly, the C´5 fluorine of 41 occupies a pocket formed by Phe340, Leu352, Ile356, Met369, Phe370, and Tyr373, anchoring the ring in place.…”