Structure‐Based Drug Design of Mineralocorticoid Receptor Antagonists to Explore Oxosteroid Receptor Selectivity

Abstract

The mineralocorticoid receptor (MR) is a nuclear hormone receptor involved in the regulation of body fluid and electrolyte homeostasis. In this study we explore selectivity triggers for a series of nonsteroidal MR antagonists to improve selectivity over other members of the oxosteroid receptor family. A biaryl sulfonamide compound was identified in a high-throughput screening (HTS) campaign. The compound bound to MR with pK =6.6, but displayed poor selectivity over the glucocorticoid receptor (GR) and the progesterone receptor (PR). Following X-ray crystallography of MR in complex with the HTS hit, a compound library was designed that explored an induced-fit hypothesis that required movement of the Met852 side chain. An improvement in MR selectivity of 11- to 79-fold over PR and 23- to 234-fold over GR was obtained. Given the U-shaped binding conformation, macrocyclizations were explored, yielding a macrocycle that bound to MR with pK =7.3. Two protein-ligand X-ray structures were determined, confirming the hypothesized binding mode for the designed compounds.

Discovery of a Novel Oral Glucocorticoid Receptor Modulator (AZD9567) with Improved Side Effect Profile

“… a Affinity of compounds for the partially purified human full length GR determined in a fluoroligand binding assay using the fluorescent polarization method b Affinity of compounds for the progesterone receptor (PR) expressed in human T47D cells and the human androgen receptor (AR) expressed in LNCaP cells, were determined in a radioligand binding assay …”

“… b Affinity of compounds for the progesterone receptor (PR) expressed in human T47D cells and the human androgen receptor (AR) expressed in LNCaP cells, were determined in a radioligand binding assay c Affinity of compounds for the human mineralcorticoid receptor (MR) ligand binding domain determined in scintillation proximity assay (SPA) d Affinity of compounds for the agonist site of the human estrogen receptor α (ERα) and human estrogen receptor β (ERβ) expressed in transfected Sf9 cells determined in a fluoligand binding assay using the fluorescence polarization method.…”

Identification of Mineralocorticoid Receptor Modulators with Low Impact on Electrolyte Homeostasis but Maintained Organ Protection

“…luciferase human MR reporter gene antagonist assay (hMR GAL4 ). 46 Docking of (R)-5 into the induced-fit model of MR in complex with 4 indicated that (R)-5 extended into all three regions of our pharmacophore model (Figure 2C). However, rac-5 exhibited poor kinetic solubility, pSol > 6.0, and low metabolic stability in human liver microsomes (HLMs) with CL int values of 120 μL/(min mg).…”

“…Selection was done by substructure searches using motifs from known binders targeting the three key regions mentioned above. Subsequent iterative screening of the selected compounds provided a series of sulfonamide benzoxazinones, as exemplified by rac -5 with pIC 50 5.2 and an efficacy extrapolated to 100% in a GAL4 luciferase human MR reporter gene antagonist assay (hMR GAL4 ) . Docking of ( R ) -5 into the induced-fit model of MR in complex with 4 indicated that ( R ) -5 extended into all three regions of our pharmacophore model (Figure C).…”

Structure-Uptake Relationship Studies of Oxazolidinones in Gram-negative ESKAPE Pathogens

“…. 57 (13). A mixture of compound 11 (152 mg, 0.4 mmol), compound 19 (122 mg, 0.48 mmol), potassium carbonate (221 mg, 1.6 mmol), and [1,1'bis(diphenylphosphino)ferrocene]dichloropalladium(II), complex with dichloromethane (33 mg, 0.04 mmol) in dioxane/H2O (v/v= 9:1, 2 mL) was stirred at 90 o C under nitrogen atmosphere.…”