Synthesis, Antifungal, and Anti-tubercular Activity of some new 7-amino-2- (Substituted aryl)-5-oxo-1,5-dihydro-[1,2,4]Triazolo[1,5- a]Pyridine-6-carbonitrile Derivatives

Abstract

A series of some 7-amino-2-(substituted aryl)-5-oxo-1,5-dihydro-[1,2,4]triazolo[1,5- a]pyridine-6-carbonitrile derivatives was synthesized by the reaction of cyanoacetohydrazone derivatives with malononitrile in presence of catalytic base piperidine and ethanol as solvent. Comparing the antifungal activity of all the investigated compounds to that of standard Amphotericin-B on Potato- Dextrose-Agar medium, compounds 1a, 1e, and 1i revealed excellent antifungal action against Aspergillus niger and Candida albicans. Using the Microplate-Alamar Blue Assay, the anti-tubercular activity of compounds 1a?1j was assessed against Mycobacterium tuberculosis H37Rv. Compared to the conventional isoniazid and ethambutol minimum inhibitory concentration of 1.6 ?g/mL, 1i and 1j had potent anti-tubercular activity at 1.6 ?g/mL, and 1b possessed moderate activity at 3.12 ?g/mL. Electron-donating groups have better anti-fungal and anti-tubercular efficacy than other substituents.. KEYWORDS :Anti-tubercular activity, Ethylcyanoacetate, Malononitrile, Microplate- Alamar Blue Assay, Potato-Dextrose-Agar medium, Triazolo[1,5-a]pyridines.