An anthrone-based Kv7.2/7.3 channel blocker with improved properties for the investigation of psychiatric and neurodegenerative disorders.

A set of novel Kv7.2/7.3 (KCNQ2/3) channel blockers was synthesized to address several liabilities of the known compounds XE991 (metabolic instability and CYP inhibition) and the clinical compound DMP 543 (acid instability, insolubility, and lipophilicity). Using the anthrone scaffold of the prior channel blockers, alternative heteroarylmethyl substituents were installed via enolate alkylation reactions. Incorporation of a pyridazine and a fluorinated pyridine gave an analog (compound 18, JDP-107) with a promising combination of potency (IC50 = 0.16 µM in a Kv7.2 thallium flux assay), efficacy in a Kv7.2/7.3 patch clamp assay, and drug-like properties.

The parmodulin NRD-21 is an allosteric inhibitor of PAR1 Gq signaling with improved anti-inflammatory activity and stability.

Novel analogs of the allosteric, biased PAR1 ligand ML161 (parmodulin 2, PM2) were prepared in order to identify potential anti-thrombotic and anti-inflammatory compounds of the parmodulin class with improved properties. Investigations of structure-activity relationships of the western portion of the 1,3-diaminobenzene scaffold were performed using an intracellular calcium mobilization assay with endothelial cells, and several heterocycles were identified that inhibited PAR1 at sub-micromolar concentrations. The oxazole NRD-21 was profiled in additional detail, and it was confirmed to act as a selective, reversible, negative allosteric modulator of PAR1. In addition to inhibiting human platelet aggregation, it showed superior anti-inflammatory activity to ML161 in a qPCR assay measuring the expression of tissue factor in response to the cytokine TNF-alpha in endothelial cells. Additionally, NRD-21 is much more plasma stable than ML161, and is a promising lead compound for the parmodulin class for anti-thrombotic and anti-inflammatory indications.