Setipiprant

Leuktriene B4 receptor 2 (BLT2) is a G-protein coupled receptor modulation of which is discussed to be a therapeutic option for healing of intestinal lesions. In this work, new BLT2 agonists were identified by a virtual screening of a repurposing library and in vitro assay of the most promising compounds. Irbesartan, an approved type-1 angiotensin II receptor (AT1) antagonist, was identified as a moderate BLT2 agonist. An initial SAR study on the irbesartan scaffold was performed resulting in the discovery of a new potent BLT2 agonist (8f, EC₅₀ = 67.6 nM). Irbesartan and 8f were shown to promote proliferation of epithelial colon cells, an effect which was reversible by a BLT2 antagonist.

Drug development is an arduous procedure, necessitating testing the interaction of a large number of potential candidates with potential interacting (macro)molecules. Therefore, any method which could provide an initial screening of potential candidate drugs might be of interest for the acceleration of the procedure, by highlighting interesting compounds, prior to in vitro and in vivo validation. In this line, we present a method which may identify potential hits, with agonistic and/or antagonistic properties on GPCR receptors, integrating the knowledge on signaling events triggered by receptor activation (GPCRs binding to Gα,β,γ proteins, and activating Gα, exchanging GDP for GTP, leading to a decreased affinity of the Gα for the GPCR). We show that, by integrating GPCR‐ligand and Gα‐GDP or ‐GTP binding in docking simulation, which correctly predicts crystallographic data, we can discriminate agonists, partial agonists, and antagonists, through a linear function, based on the ΔG (Gibbs‐free energy) of liganded‐GPCR/Gα‐GDP. We built our model using two Gαs (β2‐adrenergic and prostaglandin‐D2), four Gαi (μ‐opioid, dopamine‐D3, adenosine‐A1, rhodopsin), and one Gαo (serotonin) receptors and validated it with a series of ligands on a recently deorphanized Gαi receptor (OXER1). This approach could be a valuable tool for initial in silico validation and design of GPRC‐interacting ligands.