Novel isoniazid derivative as promising antituberculosis agent

Latent Tuberculosis: A Promising New Compound to Treat Non-Replicating and Intramacrophagic Mycobacteria

As a biologic reservoir of Mycobacterium tuberculosis (M. tb), one-quarter of the world population is infected with the well-known latent tuberculosis (LTBI). About 5–10% of LTBI patients will progress to active disease in the first years after primary infection and, despite using the recommended treatment, 20% can still reactivate the infection. A new LTBI treatment could minimize adverse effects and antibiotic resistance that can occur when the same drug is used to treat the latent and active disease. New hydrazones were evaluated, and they showed great inhibitory activity against intramacrophagic and non-replicating M. tb, commonly found at this stage of infection, in addition to bactericidal and narrow-spectrum activity. When tested against eukaryotic cells, the hydrazones showed great safety at different exposure times. In vitro, these compounds performed better than isoniazid and could be considered new candidates for LTBI treatment, which may promote greater engagement in its prescription and adherence.

Biological and Biochemical Evaluation of Isatin-Isoniazid Hybrids as Bactericidal Candidates against Mycobacterium tuberculosis

Tuberculosis remains a leading cause of mortality among infectious diseases worldwide, prompting the need to discover new drugs to fight this disease. We report here the design, synthesis, and antimycobacterial activity of isatin-mono/bis-isoniazid hybrids. Most of the compounds exhibited very high activity against Mycobacterium tuberculosis, with MICs in the range of 0.195 to 0.39 μg/ml, and exerted a more potent bactericidal effect than the standard antitubercular drug isoniazid (INH). Importantly, these compounds were found to be well tolerated at high doses (>200 μg/ml) on Vero kidney cells, leading to high selectivity indices. Two of the most promising hybrids were evaluated for activity in THP-1 macrophages infected with M. tuberculosis, among which compound 11e was found to be slightly more effective than INH. Overexpression of InhA along with cross-resistance determination of the most potent compounds, selection of resistant mutants, and biochemical analysis, allowed us to decipher their mode of action. These compounds effectively inhibited mycolic acid biosynthesis and required KatG to exert their biological effects. Collectively, this suggests that the synthesized isatin-INH hybrids are promising antitubercular molecules for further evaluation in preclinical settings.

Antimicrobial and cytotoxic activities of isoniazid connected menthone derivatives and their investigation of clinical pathogens causing infectious disease

BACKGROUND

This work is development of new molecules of isoniazid derivatives as dealing with potential of antimicrobial activity against clinical pathogens causing infectious disease. Antimicrobial of novel Mannich base derivatives can be achieved via one-pot synthesis in green chemistry approach. This method offers efficient, mild reaction conditions and high yields. In this study, totally 12 compounds (1a-l) was prepared and screened for cytotoxic and antimicrobial activities.

MATERIALS AND METHODS

Newly synthesised compounds were conformed via FT- IR, ¹H, and ¹³C NMR (Nuclear Magnetic Resonance), and mass spectra analysis. All compounds were checked antibacterial activity against gram-positive bacteria of Enterococcus faecalis, Staphylococcus aureus and gram-negative bacteria of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. All compounds were checked against antifungal activity against Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Aspergillus niger, and Microsporum audouinii. All compounds were screened for cytotoxic activity against the MCF-7 (Michigan Cancer Foundation-7) cancer cell line.

RESULT

The compound 1g was highly (MIC: 0.25 μg/mL) active against gram-negative bacterial of P. aeruginosa, whereas other compounds 1e and 1h were more active (MIC: 2 μg/mL) in K. pneumoniae and also 1g (MIC: 2 μg/mL) was more active in E. faecalis than standard ciprofloxacin. Antifungal screening, the compound 1b was highly active (MIC: 0.25 μg/mL) against C. albicance,1g (MIC: 2 μg/mL) and 1h (MIC: 4 μg/mL) was significant of active against A. fumigatus, and the compound 1c (MIC: 4 μg/mL) was extremely active in M. audouinii than clotrimazole. Compound 1g (GI₅₀ = 0.01 μM) exhibited high activity against the MCF-7 cell line, while 1b (GI₅₀ = 0.02 μM) was equipotent active compared with standard doxorubicin.

CONCLUSION

A novel set of isoniazid derivatives (1a-l) and 1h were synthesized and screened for antimicrobial and cytotoxic activities. We found some highly active molecules, which are evidencing to be a potential treatment of bacterial and fungal infection candidates.

Microwave-Assisted Synthesis of Schiff Bases of Isoniazid and Evaluation of Their Anti-Proliferative and Antibacterial Activities

Three new Schiff bases of isoniazid were synthesized using microwave-assisted synthesis and conventional condensation with aromatic aldehydes. Synthesized compounds were characterized using elemental analysis, IR, NMR, and Mass spectroscopy. Synthesized compounds were evaluated for antiproliferative activity against MCF-7 cell line. The IC50 values were from 125 to 276 µM. The compounds were also evaluated for antibacterial activity against Staphylococcus aureus and Escherichia coli. Results showed that the synthesized compounds produce significant antibacterial activity in vitro. Inhibition of compounds ranged from 13 to 18 mm.