ABSTRACT
This paper describes preparation and biological evaluation of pyrazinamide analogues. Pyrazinamide with its simple structure gives a good opportunity for further modification regarding an increase of its antimycobacterial activity. We prepared a series of compounds derived from pyrazine-2,5-dicarbonitrile with arylamino substitution in position 3. All compounds were assayed in vitro against major Mycobacterium and various Fungi species. The best activity was found in 3-{[3-(trifluoromethyl)phenyl]amino}pyrazine-2,5-dicarbonitrile 11 with the value of 6.25 micromol(-1) against M. tuberculosis H(37)Rv and moderate activity against minor Mycobacterium pathogens.
Subject(s)
Antifungal Agents/chemical synthesis , Antitubercular Agents/chemical synthesis , Nitriles/chemical synthesis , Pyrazinamide/analogs & derivatives , Pyrazinamide/chemical synthesis , Pyrazines/chemical synthesis , Absidia/drug effects , Antifungal Agents/pharmacology , Antitubercular Agents/pharmacology , Aspergillus fumigatus/drug effects , Candida/drug effects , Chromatography, High Pressure Liquid , Microbial Sensitivity Tests , Mycobacterium/drug effects , Nitriles/pharmacology , Pyrazinamide/pharmacology , Pyrazines/pharmacology , Structure-Activity Relationship , Trichosporon/drug effectsABSTRACT
Unsubstituted, halogenated and/or alkylated pyrazine-2-carboxylic acid amides connected via -CONH- bridge with substituted anilines were synthesized using currently known synthetic pathways. The synthetic approach, analytical, spectroscopic, lipophilicity and biological data of 20 newly synthesized compounds are presented. Structure-activity relationships among the chemical structures, the antimycobacterial, antifungal, photosynthesis inhibiting and antialgal activity of the evaluated substituted N-phenylpyrazine-2-carboxamides are discussed. 5-tert-Butyl-6-chloro-N-(3-trifluoromethylphenyl)pyrazine-2-carboxamide (19) has shown the highest activity against Mycobacterium tuberculosis H(37)Rv (MIC=3.13 microg/mL). The highest antifungal effect against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for N-(3-trifluoromethylphenyl)pyrazine-2-carboxamide (14, MIC=62.5 micromol/mL). The highest reduction of chlorophyll content in Chlorella vulgaris was found for pyrazine-2-carboxylic acid (3-trifluoromethylphenyl)amide (9, IC(50)=12.1 micromol/L).
Subject(s)
Amides/chemical synthesis , Anti-Bacterial Agents/chemical synthesis , Mycobacterium tuberculosis/drug effects , Pyrazines/chemical synthesis , Amides/chemistry , Amides/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Chlorella vulgaris/drug effects , Chlorella vulgaris/metabolism , Chlorocebus aethiops , Chlorophyll/metabolism , Chloroplasts/drug effects , Chloroplasts/metabolism , Herbicides/chemical synthesis , Herbicides/chemistry , Herbicides/pharmacology , Microbial Sensitivity Tests , Pyrazines/chemistry , Pyrazines/pharmacology , Spinacia oleracea/drug effects , Spinacia oleracea/metabolism , Structure-Activity Relationship , Vero CellsABSTRACT
Condensation of the corresponding chlorides of some substituted pyrazine-2-carboxylic acids (pyrazine-2-carboxylic acid, 6-chloropyrazine-2-carboxylic acid, 5-tert-butylpyrazine-2-carboxylic acid or 5-tert-butyl-6-chloropyrazine-2-carboxylic acid) with various ring-substituted aminothiazoles or anilines yielded a series of amides. The syntheses, analytical and spectroscopic data of thirty newly prepared compounds are presented. Structure-activity relationships between the chemical structures and the anti-mycobacterial, antifungal and photosynthesis-inhibiting activity of the evaluated compounds are discussed. 3,5-Bromo-4-hydroxyphenyl derivatives of substituted pyrazinecarboxylic acid, 16-18, have shown the highest activity against Mycobacterium tuberculosis H(37)Rv (54-72% inhibition). The highest antifungal effect against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for 5-tert-butyl-6-chloro-N-(4-methyl-1,3-thiazol-2-yl)pyrazine-2-carboxamide (8, MIC =31.25 micromol x mL(-1)). The most active inhibitors of oxygen evolution rate in spinach Molecules 2006, 11,243 chloroplasts were the compounds 5-tert-butyl-6-chloro-N-(5-bromo-2-hydroxyphenyl)- pyrazine-2-carboxamide (27, IC(50) = 41.9 micromol x L(-1)) and 5-tert-butyl-6-chloro-N-(1,3- thiazol-2-yl)-pyrazine-2-carboxamide (4, IC50 = 49.5 micromol x L(-1)).
