Design and synthesis of biquinolone–isoniazid hybrids as a new class of antitubercular and antimicrobial agents

• A series of biquinolone–isoniazid hybrids has been designed and synthesized.
• All the compounds were screened for antimicrobial and antituberculosis activity.
• Hybrids 7a, 7e, 7f, 7g, 7h, 7k and 7m emerged out as promising antimicrobials.
• Hybrids 7j and 7l were found to be most efficient antituberculars.
• Hybrids 7j and 7l were exhibited comparatively less toxicity.

Twenty four biquinolone–isoniazid hybrids were designed based on molecular hybridization technique and synthesized via multicomponent cyclocondensation (MCC) approach. All the newly synthesized compounds were screened for their antimicrobial and antitubercular activities. The brine shrimp bioassay was carried out to study the cytotoxicity of the synthesized compounds. Hybrids 7f (MIC = 25 μg/mL); 7a, 7e and 7m (MIC = 50 μg/mL); 7g, 7h and 7k (MIC = 62.5 μg/mL) exhibited excellent antimicrobial activity as compared with standard drugs. Hybrids 7l and 7j displayed 99% inhibition against Mycobacterium tuberculosis bacteria with better LC50 values 35.39 and 34.59 μg/mL, respectively. These results indicate that the synthesized compounds can act as leads for the development of newer antimicrobial and antitubercular compounds.

A series of biquinolone–isoniazid hybrids 7a–x has been designed and synthesized. Their antimicrobial activity against representative panel of pathogens and antitubercular activity against Mycobacterium tuberculosis H37Rv were evaluated.Figure optionsDownload as PowerPoint slide