New oxadiazole derivatives of isonicotinohydrazide in the search for antimicrobial agents: Synthesis and in vitro evaluation

Abstract

Structural modification of the front line antitubercular drug isoniazid provide a lipophilic adaptations of the drug in which hydrazide moiety of isoniazid is replaced by 1,3,4-oxadiazole heterocycles to eliminate in-vivo acetylation by arylamine N-acetyltransferase which results to form inactive acetylated drug. In the present study a series of sixteen oxadiazole derivatives were synthesized and characterized by (IR, 1H NMR, 13C NMR and Mass spectral) studies. All the synthesized compounds were evaluated for their antimicrobial activity by broth dilution method against two Gram positive strains (Bacillus subtilis and Staphylococcus aureus), two Gram negative strains (Pseudomonas aeruginosa and Escherichia coli) and fungal strain (Candida albicans and Aspergillus niger). The minimum inhibitory concentration of the compounds was in the range of 1.56-50 μg ml-1 against bacterial and fungal strain. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms. Among the synthesized derivatives 4g, 4h, 4m and 4p were found to be most effective antimicrobial compounds

Synthesis and antimicrobial evaluation of some 2,5 disubstituted 1,3,4-oxadiazole derivatives

“…Oxadiazoles constitute an important class for new drug development with various biological properties ( 1 4 5 6 7 8 9 10 11 12 ). Substituted 1,3,4-oxadiazoles at 2,5 positions are particularly important because of their antimicrobial activities against a wide range of gram-positive and gram-negative bacteria ( 6 13 14 25 26 ).…”

“…However, 1,3,4-oxadiazole is more important because of its remarkable biological activities. Compounds containing 1,3,4-oxadiazole structure possess various pharmacological effects including antibacterial, antifungal ( 1 4 5 6 7 8 9 10 ), anti-tubercular ( 11 ), anticonvulsant, anti-allergic, anti-inflammatory, cytotoxic, and insecticidal activities ( 1 6 12 ). This structure can be used as a bioisoester for carboxylic acids, esters, and carboxamides ( 6 ).…”

Spectral, optical, and cytotoxicity studies on N‐(2‐isonicotinoylhydrazine‐carbonothioyl)benzamide and its metal complexes

“…To face the increasing challenge of antimicrobial drug‐resistant microorganisms, many researches are performed to design and synthesize new compounds with potent therapeutic activity . Isoniazid has attracted much more attention due to its anti‐tuberculostatic, anti‐bacterial, and anti‐depressant properties.…”

Antibacterial Screening of Newly Synthesized Mannich Bases Derived From 5h-Dibenzo[b,f]azepine-5-Corboxamide Against Gram Positive and Gram Negative Pathogens

“…In 1912 Germen chemist Carl Mannich antibacterial, [3][4][5] antifungal, [6][7] anticonvulsant, [8] anticancer [9] and anti-inflammatory [10] agents.…”