Discovery of Highly Potent Benzimidazole Derivatives as Indoleamine 2,3-Dioxygenase-1 (IDO1) Inhibitors: From Structure-Based Virtual Screening to in Vivo Pharmacodynamic Activity.

In this study, a successful medicinal chemistry campaign that exploited virtual, biophysical, and biological investigations led to the identification of a novel class of IDO1 inhibitors based on a benzimidazole substructure. This family of compounds is endowed with an extensive bonding network in the protein active site, including the interaction with pocket C, a region not commonly exploited by previously reported IDO1 inhibitors. The tight packing of selected compounds within the enzyme contributes to the strong binding interaction with IDO1, to the inhibitory potency at the low nanomolar level in several tumoral settings, and to the selectivity toward IDO1 over TDO and CYPs. Notably, a significant reduction of L-Kyn levels in plasma, together with a potent effect on abrogating immunosuppressive properties of MDSC-like cells isolated from patients affected by pancreatic ductal adenocarcinoma, was observed, pointing to this class of molecules as a valuable template for boosting the antitumor immune system.

Identification of a novel DGKα inhibitor for XLP-1 therapy by virtual screening.

As part of an effort to identify druggable diacylglycerol kinase alpha (DGKα) inhibitors, we used an in-silico approach based on chemical homology with the two commercially available DGKα inhibitors R59022 and R59949. Ritanserin and compound AMB639752 emerged from the screening of 127 compounds, showing an inhibitory activity superior to the two commercial inhibitors, being furthermore specific for the alpha isoform of diacylglycerol kinase. Interestingly, AMB639752 was also devoid of serotoninergic activity. The ability of both ritanserin and AMB639752, by inhibiting DGKα in intact cells, to restore restimulation induced cell death (RICD) in SAP deficient lymphocytes was also tested. Both compounds restored RICD at concentrations lower than the two previously available inhibitors, indicating their potential use for the treatment of X-linked lymphoproliferative disease 1 (XLP-1), a rare genetic disorder in which DGKα activity is deregulated.

The hitchhiker's guide to the chemical-biological galaxy.

We are used to considering chemical and biological spaces as two different entities; although they represent a more-interconnected world, in fact they represent a Yin-Yang concept in drug discovery. Chemical-biological space is as vast as the universe and, as Douglas Adams famously said, 'Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is'. However, many researchers are convinced that it is not so infinite, and are designing computational and experimental tools to help identify and explore all possible chemical-biological space. Here, we provide an analysis of their approaches and discuss possible future research studies.

Transition-Metal-Free Synthesis of 2-Arylimidazolones via Cascade Reaction between Arynes and α,α'-Disubstituted α-Isocyanoacetamides.

The reaction between arynes and secondary α,α'-disubstituted α-isocyanoacetamides was developed to access 2-arylimidazolones of structural diversity and complexity in a straightforward manner.