Evaluating Triazole-Substituted Pyrrolopyrimidines as CSF1R Inhibitors.

Area of Science:

• Medicinal Chemistry
• Drug Discovery
• Molecular Biology

Background:

• 6-Aryl-7H-pyrrolo[2,3-d]pyrimidin-4-amines are recognized for their colony-stimulating factor 1 receptor (CSF1R) inhibitory properties.
• CSF1R is a key target in various therapeutic areas, necessitating the development of novel inhibitors.

Purpose of the Study:

• To synthesize and evaluate novel 1,2,3-triazole analogues as potential CSF1R inhibitors.
• To assess the enzymatic and cellular activity of synthesized compounds against CSF1R.
• To investigate the kinase selectivity profile and binding modes of the most promising analogues.

Main Methods:

• Synthesis of 28 novel 1,2,3-triazole derivatives.
• Enzymatic IC50 profiling and Ba/F3 cellular assays to determine CSF1R inhibitory potency.
• Kinase panel screening and molecular docking studies against CSF1R X-ray structures.

Main Results:

• 27 out of 28 synthesized triazole analogues demonstrated superior enzymatic IC50 values compared to the reference drug PLX-3397.
• Three derivatives achieved CSF1R Ba/F3 cellular IC50 values below 1 µM.
• Compound 27a exhibited high selectivity for CSF1R over related kinases but also inhibited ABL, SRC, and YES kinases; molecular docking revealed distinct binding poses.

Conclusions:

• The synthesized 1,2,3-triazole analogues represent a promising new class of CSF1R inhibitors with significant potency.
• Compound 27a warrants further investigation due to its potent CSF1R inhibition, selectivity profile, and unique binding modes.
• These findings support the continued exploration of triazole scaffolds for CSF1R-targeted therapies.