1,3,4-oxadiazoles with effective anti-mycobacterial activity

Area of Science:

• Medicinal Chemistry
• Antimicrobial Drug Discovery
• Mycobacterial Infections

Background:

• The urgent need for novel therapeutics against tuberculosis (TB) and nontuberculous mycobacteria (NTM) infections persists.
• Existing treatments face challenges due to drug resistance and toxicity.
• Synthetic heterocyclic compounds, particularly 1,3,4-oxadiazoles, are explored for their potential antimicrobial properties.

Purpose of the Study:

• To evaluate the antimycobacterial activity of two novel synthetic 1,3,4-oxadiazole derivatives, LMM6 and LMM11.
• To assess the synergistic potential of LMM6 and LMM11 in combination with established anti-TB drugs against Mycobacterium tuberculosis.
• To determine the in vitro cytotoxicity of these compounds in mammalian cell lines.

Main Methods:

• Minimum Inhibitory Concentration (MIC) assays were performed against Mycobacterium tuberculosis (H37Rv and resistant strains), NTM, and other bacterial species.
• Combinatory effects of LMM6 and LMM11 with anti-TB drugs were evaluated.
• In vitro cytotoxicity was assessed using HeLa and VERO cell lines.

Main Results:

• LMM6 and LMM11 exhibited significant activity against M. tuberculosis, with MIC values ranging from 8.27 to 70.30 µM.
• LMM6 showed potent activity against M. smegmatis, M. szulgai, and M. kansasii, while LMM11 was active against M. szulgai and M. smegmatis.
• Synergistic and modulatory effects were observed when LMM6 and LMM11 were combined with anti-TB drugs. Both compounds displayed selectivity for mycobacteria over mammalian cells.

Conclusions:

• The novel 1,3,4-oxadiazole derivatives, LMM6 and LMM11, possess promising antimycobacterial activity, particularly against M. tuberculosis.
• These compounds demonstrate potential for synergistic interactions with existing anti-TB drugs, offering new therapeutic avenues.
• LMM6 and LMM11 represent valuable leads for the development of next-generation antimycobacterial agents.