Synthesis and anti-inflammatory activity of benzal-3-pentadecylaryloxyalkyl carboxylic acid hydrazides and 2-benzalamino-5-(3′-pentadecylaryloxyalkyl)-1,3,4-oxadiazoles

Novel 1,3,4-oxadiazole motifs bearing a quinoline nucleus: synthesis, characterization and biological evaluation of their antimicrobial, antitubercular, antimalarial and cytotoxic activities

Quinoline–oxadiazole hybrids: a new class of antimicrobial, antitubercular and antimalarial compounds.

Synthesis and evaluation of novel 4-nitropyrrole-based 1,3,4-oxadiazole derivatives as antimicrobial and anti-tubercular agents

We report synthesis and antimicrobial evaluation of 42 novel 4-nitropyrrole-based 1,3,4-oxadiazoles. The synthesized molecules were evaluated for anti-bacterial, anti-fungal and anti-tubercular activities. Promisingly, most of the compounds showed equal or more potency than standard ciprofloxacin against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compound 5e exhibited highest anti-tubercular activity (0.46 μg/mL) close to that of standard Isoniazid (0.40 μg/mL). Equal antifungal activity (1.56 μg/mL) compared to standard Amphotericin-B was shown by most of the compounds. All the N-methylated compounds showed more potent to equal activity against MSSA (MIC 0.39-1.56 μg/mL) and MRSA (MIC 0.78-1.56 μg/mL). All compounds were tested for mammalian cell toxicity using VERO cell line and were found to be non-toxic.

Multicomponent Synthesis of Novel 2-Aryl-5-((1-aryl-1H-1,2,3-triazol-4-yl)methylthio)-1,3,4-oxadiazoles using CuI as Catalyst and their Antimicrobial Evaluation

A series of novel 2-aryl-5-((1-aryl-1H-1,2,3-triazol-4-yl)methylthio)-1,3,4-oxadiazoles have been synthesised by C–S bond formation and azide–alkyne cyclocondensation between [5-(aryl)-[1,3,4]oxadiazol-2-yl]methanethiol, propargyl bromide, and substituted aryl azides in one pot with an aim to explore their effect on the in vitro growth of microorganisms causing microbial infection. In vitro antibacterial activity was determined against four strains, namely Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa and antifungal activity against two fungal strains, namely Aspergillus niger and Aspergillus flavus.

Synthesis of Some New 2-(6-Methoxy-2-Naphthyl)- 5-Aryl-1,3,4-Oxadiazoles as Possible Non-steroidal Anti-inflammatory and Analgesic Agents

The synthesis of some new 2-(6-methoxy-2-naphthyl)-5-aryl-1,3,4-oxadiazoles (4a-k) has been described. Ethyl-6-methoxy-2-naphthoate (1) yielded on treatment with hydrazine hydrate to 6-methoxy-2-naphthoic acid hydrazide (2). Compound 2 reacted with substituted aromatic carboxylic acids (3a-k) in phosphorus oxychloride yielded 2-(6-methoxy-2-naphthyl)-5-aryl-1,3,4-oxadiazoles (4a-k). Newly synthesized compounds were characterized by IR, (1)H-NMR and mass spectral data. All the compounds were screened for their anti-inflammatory and analgesic activity. Compound 4j exhibited promising anti-inflammatory and analgesic activities.

Synthesis of Schiff bases of 2-amino-5-aryl-1, 3, 4-oxadiazoles and their evaluation for antimicrobial activities

Twenty Schiff bases of 2-amino-5-aryl-1,3,4-oxadiazoles have been synthesized with different aromatic aldehydes. The structures of the compounds were confirmed by nitrogen analysis, IR and 13C-NMR spectral data. The antibacterial properties of the compounds were investigated against Proteus mirabilis (MTCC-425), Pseudomonas aeruginosa (MTCC-424), Bacillus subtilis (MTCC-619) and Staphylococcus aureus (MTCC-96) using the broth dilution method. The most active compounds were 4c (64 microg/ml), 4f (68 microg/ml), 4m (64 microg/ml) and 4q (62 microg/ml). The antifungal screening of the compounds were carried out using Aspergillus niger (MTCC-1344) and Candida albicans (MTCC-227) using the broth dilution method. Active compounds were 4g (52 microg/ml), 4h (56 microg/ml), 4l (60 microg/ml), 4m (58 microg/ml).