Structural Investigations on 2-Amidobenzimidazole Derivatives as New Inhibitors of Protein Kinase CK1 Delta

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Protein kinase CK1δ (CK1δ) regulates critical cellular processes like cell cycle, DNA repair, and apoptosis.
• Aberrant CK1δ activity is implicated in cancer, neurodegenerative diseases, and sleep disorders.
• CK1δ inhibitors exhibit anticancer and neuroprotective effects in preclinical models.

Purpose of the Study:

• To design and synthesize novel ATP-competitive inhibitors targeting CK1δ.
• To identify potent CK1δ inhibitors with potential therapeutic applications.

Main Methods:

• Synthesis of benzimidazole-2-amino derivatives (compounds 1-32) with variations in benzo ring substituents and pyrazole-containing acyl moieties.
• In vitro kinase inhibition assays to determine CK1δ inhibitory activity.
• Molecular docking and dynamics simulations to elucidate inhibitor-kinase interactions.

Main Results:

• Derivatives with a (1H-pyrazol-3-yl)-acetyl moiety on the benzimidazol-2-amino scaffold (13-32) showed low micromolar CK1δ inhibitory activity.
• The 5-cyano substituent on the benzo ring yielded the most potent inhibitor, compound 23, with nanomolar potency (IC50 = 98.6 nM).
• Molecular modeling studies provided insights into the binding interactions of the inhibitors with CK1δ.

Conclusions:

• Novel benzimidazole derivatives effectively inhibit protein kinase CK1δ.
• Compound 23 represents a highly potent CK1δ inhibitor with potential for further drug development.
• The structure-activity relationship and molecular interactions provide a basis for designing future CK1δ-targeting therapeutics.