Computer-aided design and synthesis of tetra-aryl-substituted alkenes and their bioevaluation as a selective modulator of estrogen-related receptor γ

International Union of Basic and Clinical Pharmacology CXIII: Nuclear Receptor Superfamily-Update 2023

The NR superfamily comprises 48 transcription factors in humans that control a plethora of gene network programs involved in a wide range of physiologic processes. This review will summarize and discuss recent progress in NR biology and drug development derived from integrating various approaches, including biophysical techniques, structural studies, and translational investigation. We also highlight how defective NR signaling results in various diseases and disorders and how NRs can be targeted for therapeutic intervention via modulation via binding to synthetic lipophilic ligands. Furthermore, we also review recent studies that improved our understanding of NR structure and signaling. SIGNIFICANCE STATEMENT: Nuclear receptors (NRs) are ligand-regulated transcription factors that are critical regulators of myriad physiological processes. NRs serve as receptors for an array of drugs, and in this review, we provide an update on recent research into the roles of these drug targets.

Synthesis of Multisubstituted Olefins through Regio- and Stereoselective Addition of Interelement Compounds Having B-Si, B-B, and Cl-S Bonds to Alkynes, and Subsequent Cross-Couplings

Multisubstituted olefins are fundamental motifs in organic compounds. In this account, we describe the synthesis of organic molecules bearing an olefinic moiety by the transition-metal-catalyzed regio- and stereoselective addition of a variety of interelement compounds to alkynes. Regio- and stereoselective silaboration, diborylation, and chlorothiolation have been achieved by using the transition-metal catalysts. The subsequent cross-coupling reactions of the boron-containing alkenes to install various aryl groups afforded the corresponding tri- and tetraarylated olefins. This account describes our research on the highly regio- and stereoselective synthesis of multifunctionalized olefins such as tetraarylethenes with four different aryl groups.

In vitro metabolism of an estrogen-related receptor γ modulator, GSK5182, by human liver microsomes and recombinant cytochrome P450s

GSK5182 (4-[(Z)-1-[4-(2-dimethylaminoethyloxy)phenyl]-hydroxy-2-phenylpent-1-enyl]phenol) is a specific inverse agonist for estrogen-related receptor γ, a member of the orphan nuclear receptor family that has important functions in development and homeostasis. This study was performed to elucidate the metabolites of GSK5182 and to characterize the enzymes involved in its metabolism. Incubation of human liver microsomes with GSK5182 in the presence of NADPH resulted in the formation of three metabolites, M1, M2 and M3. M1 and M3 were identified as N-desmethyl-GSK5182 and GSK5182 N-oxide, respectively, on the basis of liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis. M2 was suggested to be hydroxy-GSK5182 through interpretation of its MS/MS fragmentation pattern. In addition, the specific cytochrome P450 (P450) and flavin-containing monooxygenase (FMO) isoforms responsible for GSK5182 oxidation to the three metabolites were identified using a combination of correlation analysis, chemical inhibition in human liver microsomes and metabolism by expressed recombinant P450 and FMO isoforms. GSK5182 N-demethylation and hydroxylation is mainly mediated by CYP3A4, whereas FMO1 and FMO3 contribute to the formation of GSK5182 N-oxide from GSK5182. The present data will be useful for understanding the pharmacokinetics and drug interactions of GSK5182 in vivo.

Synthesis and library construction of privileged tetra-substituted Δ5-2-oxopiperazine as β-turn structure mimetics

In this study, we developed an efficient and practical procedure for the synthesis of tetra-substituted Δ5-2-oxopiperazine that mimics the bioactive β-turn structural motif of proteins. This synthetic route is robust and modular enough to accommodate four different substituents to obtain a high level of molecular diversity without any deterioration in stereochemical enrichment of the natural and unnatural amino acids. Through the in silico studies, including a distance calculation of side chains and a conformational overlapping of our model compound with a native β-turn structure, we successfully demonstrated the conformational similarity of tetra-substituted Δ5-2-oxopiperazine to the β-turn motif. For the library construction in a high-throughput manner, the fluorous tag technology was adopted with the use of a solution-phase parallel synthesis platform. A 140-membered pilot library of tetra-substituted Δ5-2-oxopiperazines was achieved with an average purity of 90% without further purification.

Regioselective construction and screening of 1,3-disubstituted tetrahydroindazolones in enantiomerically pure pairs

In this paper, we describe a regioselective synthetic pathway for enantiopure 1,3-disubstituted tetrahydroindazolone derivatives via the condensation of 2-acylcyclohexane-1,3-dione with various alkyl- and arylhydrazines using the steric effects of a Boc-protected pyrrolidine ring. This synthetic method has a broad scope for substrate generality for various hydrazines with excellent regioselectivity. To maximize the molecular diversity, further diversifications of 1,3-disubstituted tetrahydroindazolones were pursued by systematic N-modification of the secondary amine of the pyrrolidine ring using solution-phase parallel synthesis with polymer-supported reagents. A library containing a total of 272 drug-like tetrahydroindazolones, including 85 enantiomeric pairs, was constructed; the average purity, without further purification, was 95%.

ERR receptors as potential targets in osteoporosis

The bone fragility and increased fracture risk associated with osteoporosis in post-menopausal women is a major public health concern. Current treatments for osteoporosis relying on hormone replacement therapies are suspected to have an association with increased breast cancer risk, highlighting the need for identifying new potential targets in bone. Recent data suggest that the estrogen-related receptor (ERR)α, an orphan nuclear receptor, represses osteoblast differentiation, and that its deletion in knockout mouse models results in increased mineral density. Furthermore, modulation of ERRα activity reduces proliferation and tumorigenesis of breast cancer cells. These results indicated that inhibition of ERRα might provide a treatment for osteoporosis without displaying adverse effects in breast cancer. This review focuses on the role of the ERR receptors, and in particular ERRα, in the differentiation of bone precursor cells and its consequences on bone homeostasis, and discusses the possible grounds for the discrepancies reported in the literature.