Collective Synthesis of Highly Oxygenated (Furano)germacranolides Derived from Elephantopus mollis and Elephantopus tomentosus.

Germacranolides, secondary metabolites produced by plants, have garnered academic and industrial interest due to their diverse and complex topology as well as a wide array of pharmacological activities. Molephantin, a highly oxygenated germacranolide isolated from medicinal plants, Elephantopus mollis and Elephantopus tomentosus, has exhibited antitumor, inflammatory, and leishmanicidal activities. Its chemical structure is based on a highly strained ten-membered macrocyclic backbone with an (E,Z)-dienone moiety, which is fused with an α-methylene-γ-butyrolactone and adorned with four successive stereogenic centers.

Withaferin A, a polyfunctional pharmacophore that includes covalent engagement of IPO5, is an inhibitor of influenza A replication.

Withaferin A, a natural steroidal lactone found in the extracts of Withania somnifera, is used extensively in traditional medicine and part of an ancient remedy in ayurvedic medicine. Prior investigations into its mode of action have shown withaferin to be a polyfunctional pharmacophore with the covalent engagement of a multitude of therapeutic targets. Herein, we report that withaferin A is also a covalent inhibitor of IPO5, an importin that translocates cargos from the cytosol to the nucleus.

Identification of a Covalent Importin-5 Inhibitor, Goyazensolide, from a Collective Synthesis of Furanoheliangolides.

Sesquiterpenes are a rich source of covalent inhibitors with a long history in traditional medicine and include several important therapeutics and tool compounds. Herein, we report the total synthesis of 16 sesquiterpene lactones via a build/couple/pair strategy, including goyasensolide. Using an alkyne-tagged cellular probe and proteomics analysis, we discovered that goyazensolide selectively targets the oncoprotein importin-5 (IPO5) for covalent engagement.

The Nuclear Transport Protein Importin-5: A Promising Target in Oncology and Virology.

Cellular homeostasis importantly relies on the correct nucleoplasmic distribution of a large number of RNA molecules and proteins, which are shuttled by specialized transport receptors. The nuclear import receptor importin-5, also called IPO5, RanBP5 or karyopherin β3, mediates the translocation of proteins to the nucleus, and thus regulates critical signaling pathways and cellular functions. The normal function of IPO5 appears to be disrupted in cancer cells due to aberrant overexpression.

HDX-MS reveals structural determinants for RORγ hyperactivation by synthetic agonists.

Members of the nuclear receptor (NR) superfamily regulate both physiological and pathophysiological processes ranging from development and metabolism to inflammation and cancer. Synthetic small molecules targeting NRs are often deployed as therapeutics to correct aberrant NR signaling or as chemical probes to explore the role of the receptor in physiology. Nearly half of NRs do not have specific cognate ligands (termed orphan NRs) and it's unclear if they possess ligand dependent activities.

Identification of potent RORβ modulators: Scaffold variation.

We sought to develop RORβ-selective probe molecules in order to investigate the function of the receptor in vitro and in vivo and its role in the pathophysiology of disease. To accomplish this, we modified a potent dual RORβ/RORγ inverse agonist from the primary literature with the goal of improving selectivity for RORβ vs RORγ. Truncation of the Western portion of the molecule ablated activity at RORγ and led to a potent series of RORβ modulators.

Design, synthesis, and evaluation of simple phenol amides as ERRγ agonists.

Herein we report the design and synthesis of a series of simple phenol amide ERRγ agonists based on a hydrazone lead molecule. Our structure activity relationship studies in this series revealed the phenol portion of the molecule to be required for activity. Attempts to replace the hydrazone with more suitable chemotypes led to a simple amide as a viable alternative.

Identification of an aminothiazole series of RORβ modulators.

Crystallography has identified stearic acid, ALRT 1550 and ATRA as ligands that bind RORβ, however, none of these molecules represent good starting points to develop optimized small molecule modulators. Recently, Compound 1 was identified as a potent dual RORβ and RORγ inverse agonist with no activity towards RORα (Fig. 1).

Substituted α-mercaptoketones, new types of specific neprilysin inhibitors.

New neprilysin inhibitors containing an α-mercaptoketone HSC(RR)CO group, as zinc ligand were designed. Two parameters were explored for potency optimization: the size of the inhibitor which could interact with the S, S' or S' domain of the enzyme and the nature of the substituents R, R of the mercaptoketone group. Introduction of a cyclohexyl chain in R, R position and a (3-thiophen)benzyl group in position R (compound 12n) yielded to the most potent inhibitor of this series with a Ki value of 2±0.

Covalent inhibitors: an opportunity for rational target selectivity.

There is a resurging interest in compounds that engage their target through covalent interactions. Cysteine's thiol is endowed with enhanced reactivity, making it the nucleophile of choice for covalent engagement with a ligand aligning an electrophilic trap with a cysteine residue in a target of interest. The paucity of cysteine in the proteome coupled to the fact that closely related proteins do not necessarily share a given cysteine residue enable a level of unprecedented rational target selectivity.

N-Arylsulfonyl Indolines as Retinoic Acid Receptor-Related Orphan Receptor γ (RORγ) Agonists.

The nuclear retinoic acid receptor-related orphan receptor γ (RORγ; NR1F3) is a key regulator of inflammatory gene programs involved in T helper 17 (T 17) cell proliferation. As such, synthetic small-molecule repressors (inverse agonists) targeting RORγ have been extensively studied for their potential as therapeutic agents for various autoimmune diseases. Alternatively, enhancing T 17 cell proliferation through activation (agonism) of RORγ may boost an immune response, thereby offering a potentially new approach in cancer immunotherapy.

Synthesis of 2-aryl-2H-tetrazoles via a regioselective [3+2] cycloaddition reaction.

A regioselective cycloaddition reaction of arenediazonium salts with trimethylsilyldiazomethane is reported. A series of 2-aryltetrazoles were obtained in good to moderate yields with wide functional group compatibility. Furthermore, this cycloaddition reaction opens the way to build up the versatile intermediate 2-aryl-5-bromotetrazole.

Randomised, double-blind, placebo-controlled, dose-escalating phase I study of QGC001, a centrally acting aminopeptidase a inhibitor prodrug.

Background And Objectives: Inhibition of brain aminopeptidase A (APA), which converts angiotensin II into angiotensin III, has emerged as a novel antihypertensive treatment, as demonstrated in several experimental animal models. QGC001 (originally named RB150) is a prodrug of the specific and selective APA inhibitor EC33, and as such it is the prototype of a new class of centrally acting antihypertensive agents. Given by the oral route in hypertensive rats, it enters the brain and generates EC33, which blocks the brain renin-angiotensin system activity and normalises blood pressure.