Pyridine embedded 1,3,4-oxadiazole derivatives: Design, synthesis, molecular docking and antitubercular activity...

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Microbiology

Background:

• Tuberculosis remains a significant global health threat, necessitating the development of new antitubercular agents.
• The emergence of drug-resistant Mycobacterium tuberculosis strains highlights the urgent need for novel therapeutic strategies.
• Pyridine-embedded 1,3,4-oxadiazole scaffolds offer a promising structural motif for antitubercular drug discovery.

Purpose of the Study:

• To synthesize and characterize a series of novel pyridine-embedded 1,3,4-oxadiazole derivatives (OXn series) with varying long-chain alkoxy groups.
• To investigate the in vitro antitubercular activity of the synthesized compounds against Mycobacterium tuberculosis.
• To explore the potential interactions of these derivatives with the mycobacterial InhA enzyme through molecular docking.

Main Methods:

• Systematic synthesis of pyridine-embedded 1,3,4-oxadiazole derivatives bearing decyloxy, dodecyloxy, tetradecyloxy, and hexadecyloxy groups.
• Evaluation of in vitro antitubercular activity using standard microbiological assays against Mycobacterium tuberculosis H37Rv.
• Molecular docking simulations against the mycobacterial InhA enzyme to predict binding interactions.

Main Results:

• Successful synthesis of the OXn series of compounds with terminal long-chain alkoxy groups.
• Compound OX-14 demonstrated significant in vitro antitubercular activity with a Minimum Inhibitory Concentration (MIC) of 32.0 μg/mL and an IC50 value of 10.4 μg/mL.
• Molecular docking studies provided insights into the potential binding modes of the derivatives with the InhA enzyme.

Conclusions:

• The synthesized pyridine-embedded 1,3,4-oxadiazole derivatives, particularly OX-14, show promising antitubercular activity.
• The long-chain alkoxy groups appear to enhance lipophilicity, potentially aiding in mycobacterial cell membrane penetration.
• Further optimization of the OX-14 scaffold could lead to the development of potent new antitubercular agents.