Core Modifications of GSK3335103 toward Orally Bioavailable αβ Inhibitors with Improved Synthetic Tractability.

The αβ integrin has been identified as a target for the treatment of fibrotic diseases, based on the role it has in activating TGF-β, a protein implicated in the pathogenesis of fibrosis. However, the development of orally bioavailable αβ inhibitors has proven challenging due to the zwitterionic pharmacophore required to bind to the RGD binding site. This work describes the design and development of a novel, orally bioavailable series of αβ inhibitors, developing on two previously published αβ inhibitors, GSK3008348 and GSK3335103.

Small Molecule Ligands of the BET-like Bromodomain, BRD3, Affect Survival, Oviposition, and Development.

Schistosomiasis is a disease affecting >200 million people worldwide, but its treatment relies on a single agent, praziquantel. To investigate new avenues for schistosomiasis control, we have conducted the first systematic analysis of bromodomain-containing proteins (BCPs) in a causative species, . Having identified 29 putative bromodomains (BRDs) in 22 proteins, we selected BRD3, a tandem BRD-containing BCP that shows high similarity to the human bromodomain and extra terminal domain (BET) family, for further studies.

Structure-Guided Design of a Domain-Selective Bromodomain and Extra Terminal N-Terminal Bromodomain Chemical Probe.

Small-molecule-mediated disruption of the protein-protein interactions between acetylated histone tails and the tandem bromodomains of the bromodomain and extra-terminal (BET) family of proteins is an important mechanism of action for the potential modulation of immuno-inflammatory and oncology disease. High-quality chemical probes have proven invaluable in elucidating profound BET bromodomain biology, with seminal publications of both pan- and domain-selective BET family bromodomain inhibitors enabling academic and industrial research. To enrich the toolbox of structurally differentiated N-terminal bromodomain (BD1) BET family chemical probes, this work describes an analysis of the GSK BRD4 bromodomain data set through a lipophilic efficiency lens, which enabled identification of a BD1 domain-biased benzimidazole series.

Identification and Optimization of a Ligand-Efficient Benzoazepinone Bromodomain and Extra Terminal (BET) Family Acetyl-Lysine Mimetic into the Oral Candidate Quality Molecule I-BET432.

The bromodomain and extra terminal (BET) family of proteins are an integral part of human epigenome regulation, the dysregulation of which is implicated in multiple oncology and inflammatory diseases. Disrupting the BET family bromodomain acetyl-lysine (KAc) histone protein-protein interaction with small-molecule KAc mimetics has proven to be a disease-relevant mechanism of action, and multiple molecules are currently undergoing oncology clinical trials. This work describes an efficiency analysis of published GSK pan-BET bromodomain inhibitors, which drove a strategic choice to focus on the identification of a ligand-efficient KAc mimetic with the hypothesis that lipophilic efficiency could be drastically improved during optimization.

Synthesis of Fluorinated Alkyl Aryl Ethers by Palladium-Catalyzed C-O Cross-Coupling.

Herein, we report a highly effective protocol for the cross-coupling of (hetero)aryl bromides with fluorinated alcohols using the commercially available precatalyst BuBrettPhos Pd G3 and CsCO in toluene. This Pd-catalyzed coupling features a short reaction time, excellent functional group tolerance, and compatibility with electron-rich and -poor (hetero)arenes. The method provides access to F-labeled trifluoroethyl ethers by cross-coupling with [F]trifluoroethanol.

Free-Wilson Analysis of Comprehensive Data on Phosphoinositide-3-kinase (PI3K) Inhibitors Reveals Importance of -Methylation for PI3Kδ Activity.

Phosphoinositide-3-kinase δ (PI3Kδ) is a critical regulator of cell growth and transformation and has been explored as a therapeutic target for a range of diseases. Through the exploration of the thienopyrimidine scaffold, we have identified a ligand-efficient methylation that leads to remarkable selectivity for PI3Kδ over the closely related isoforms. Interrogation through the Free-Wilson analysis highlights the innate selectivity the thienopyrimidine scaffold has for PI3Kδ and provides a predictive model for the activity against the PI3K isoforms.

Sex steroids regulate skin pigmentation through nonclassical membrane-bound receptors.

The association between pregnancy and altered cutaneous pigmentation has been documented for over two millennia, suggesting that sex hormones play a role in regulating epidermal melanocyte (MC) homeostasis. Here we show that physiologic estrogen (17β-estradiol) and progesterone reciprocally regulate melanin synthesis. This is intriguing given that we also show that normal primary human MCs lack classical estrogen or progesterone receptors (ER or PR).

Sequential Ketene Generation from Dioxane-4,6-dione-keto-dioxinones for the Synthesis of Terpenoid Resorcylates.

Trapping of the ketene generated from the thermolysis of 2-methyl-2-phenyl-1,3-dioxane-4,6-dione-keto-dioxinone at 50 °C with primary, secondary, or tertiary alcohols gave the corresponding dioxinone β-keto-esters in good yield under neutral conditions. These intermediates were converted by palladium(0)-catalyzed decarboxylative allyl migration and aromatization into the corresponding β-resorcylates. These transformations were applied to the syntheses of the natural products (±)-cannabiorcichromenic and (±)-daurichromenic acid.

β-Keto-dioxinones and β,δ-diketo-dioxinones in biomimetic resorcylate total synthesis.

Resorcylates are a large group of bioactive natural products that are biosynthesized from acetate and malonate units via the intermediacy of polyketides. These polyketides undergo cyclization reactions to introduce the aromatic core. The bioactivities of the resorcylates including resorcylate macrocyclic lactones include anticancer, antimalarial, mycotoxicity, antifungal, and antibiotic properties, and several compounds in the series are already in use in medicine.