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.

Dopamine-Mediated Vanillin Multicomponent Derivative Synthesis via Grindstone Method: Application of Antioxidant, Anti-Tyrosinase, and Cytotoxic Activities.

PURPOSE: This study aimed to determine the extent of contribution of dopamine to antioxidant and anti-tyrosinase activities, by dopamine addition to vanillin. This study achieved the synthesis of dopamine-associated vanillin Mannich base derivatives prepared via a one-step reaction involving a green chemistry approach, and investigation of antioxidant and anti-tyrosinase activities. METHODS: Novel one-pot synthesis of Mannich base dopamine-connected vanillin (1a-l) derivatives can be achieved via green chemistry without using a catalyst. Newly-prepared compounds were characterised with FTIR and NMR (1H and 13C) spectra, mass spectra, and elemental analyses. In total, 12 compounds (1a-l) were synthesised and their antioxidant and anti-tyrosinase activities evaluated. Antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), hydrogen peroxide (H2O2), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and diammonium assays, ABTS•+ radical scavenging, and linoleic acid peroxidation were used to screen all synthesised compounds (1a-l) for anti-tyrosinase activities and cytotoxicity against MCF-7 and Vero cell lines;. RESULTS: The compound 1k inhibited (IC50:11.02µg/mL) the DPPH-scavenging activity to a greater extent than the standard BHT (IC50:25.17µg/mL), and showed high activity in H2O2 and NO scavenging assays. Compound 1e was more potent (96.21%) against ABTS and compound 1k was more potent (95.28%) against 2,2'-azobis(2-amidinopropane)dihydrochloride antioxidant than the standard trolox. All synthesised compounds were screened for anti-tyrosinase inhibitory activity. Compound 1e had higher activity against tyrosinase (IC50=10.63 µg/mL), than kojic acid (IC50=21.52µg/mL), and was more cytotoxic (GI50 0.01µM) against MCF-7 cell line than the doxorubicin standard and other tested compounds. CONCLUSION: In this study, all compounds were found to possess significant antioxidant and anti-tyrosinase activities. Compounds 1e and 1k performed well, compared with other compounds, in all assays. In addition, this study successfully identified several promising molecules that exhibited antioxidant and anti-tyrosinase activities.