Discovery and characterization of the N-phenyl-N′-naphthylurea class of p38 kinase inhibitors

Cross-Coupling Reactions of 5-Bromo-1,2,3-triazine

An efficient Pd catalyzed cross-coupling method for 5-bromo-1,2,3-triazine is described. Optimization of the reaction conditions allowed for the preparation of a representative scope of (hetero)aryl-1,2,3-triazines (20 examples, up to 97% yield). The reaction scope was evaluated using a data science enabled boronic acid chemical space to assess the generality of the method. Additionally, diversification of the resulting products enabled the preparation of pyrimidines and pyridines in yields of up to 80% and in only two steps.

Quantitative Interpretation of Intracellular Drug Binding and Kinetics Using the Cellular Thermal Shift Assay

Evidence of physical interaction with the target protein is essential in the development of chemical probes and drugs. The cellular thermal shift assay (CETSA) allows evaluation of drug binding in live cells but lacks a framework to support quantitative interpretations and comparisons with functional data. We outline an experimental platform for such analysis using human kinase p38α. Systematic variations to the assay's characteristic heat challenge demonstrate an apparent loss of compound potency with an increase in duration or temperature, in line with expectations from the literature for thermal shift assays. Importantly, data for five structurally diverse inhibitors can be quantitatively explained using a simple model of linked equilibria and published binding parameters. The platform further distinguishes between ligand mechanisms and allows for quantitative comparisons of drug binding affinities and kinetics in live cells and lysates. We believe this work has broad implications in the appropriate use of the CETSA for target and compound validation.

Evaluation of a semi-automated workflow for fragment growing

Intelligent Automatic Design (IADE) is an expert system developed at Novartis to identify nonclassical bioisosteres. In addition to bioisostere searching, one could also use IADE to grow a fragment bound to a protein. Here we report an evaluation of IADE as a tool for fragment growing. Three examples from the literature served as test cases. In all three cases, IADE generated close analogues of the published compounds and reproduced their crystallographic binding modes. This exercise validated the use of the IADE system for fragment growing. We have also gained experience in optimizing the performance of IADE for this type of application.