title: Substituted pyrazinecarboxamides: synthesis and biological evaluation.
abstract: 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)).
authors.affiliation: Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic. martin.dolezal@faf.cuni.cz
authors.forename: Martin
authors.initials: M
authors.lastname: Dolezal
authors.forename: Lukas
authors.initials: L
authors.lastname: Palek
authors.forename: Jarmila
authors.initials: J
authors.lastname: Vinsova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Buchta
authors.forename: Josef
authors.initials: J
authors.lastname: Jampilek
authors.forename: Katarina
authors.initials: K
authors.lastname: Kralova
mesh_terms: D000577:Amides / Q000138:chemical synthesis* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000494:pharmacology; D002264:Carboxylic Acids / Q000737:chemistry*; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D011719:Pyrazines / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000577:Amides; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D002264:Carboxylic Acids; D011719:Pyrazines