title: Novel pyrazole integrated 1,3,4-oxadiazoles: synthesis, characterization and antimicrobial evaluation.
abstract: A novel series of 2-(5-methyl-1,3-diphenyl-1H-pyrazol-4-yl)-5-phenyl-1,3,4-oxadiazoles 7(a-m) were synthesized either by cyclization of N'-benzoyl-5-methyl-1,3-diphenyl-1H-pyrazole-4-carbohydrazide 4a using POCl3 at 120°C or by oxidative cyclization of hydrazones derived from various arylaldehyde and (E)-N'-benzylidene-5-methyl-1,3-diphenyl-1H-pyrazole-4-carbohydrazide 5(a-d) using chloramine-T as oxidant. Newly synthesized compounds were characterized by analytical and spectral (IR, (1)H NMR, (13)C NMR and LC-MS) methods. The synthesized compounds were evaluated for their antimicrobial activity and were compared with standard drugs. The compounds demonstrated potent to weak antimicrobial activity. Among the synthesized compounds, compound 7m emerged as an effective antimicrobial agent, while compounds 7d, 7f, 7i and 7l showed good to moderate activity. The minimum inhibitory concentration of the compounds was in the range of 20-50μgmL(-1) against bacteria and 25-55μgmL(-1) against fungi. The title compounds represent a novel class of potent antimicrobial agents.
authors: Department of Chemistry, Yuvaraja's College, University of Mysore, Mysore 570 005, India.
authors: Srikantamurthy
authors: S
authors: Ningaiah
authors: Department of Chemistry, Yuvaraja's College, University of Mysore, Mysore 570 005, India. Electronic address: kbu68umesha@rediffmail.com.
authors: Umesha K
authors: UK
authors: Bhadraiah
authors: Department of Studies in Chemistry, Manasagangotri, University of Mysore, India.
authors: Shridevi D
authors: SD
authors: Doddaramappa
authors: Department of Chemistry, Yuvaraja's College, University of Mysore, Mysore 570 005, India.
authors: Shubakara
authors: S
authors: Keshavamurthy
authors: Department of Biotechnology, Manasagangotri, University of Mysore, Mysore 570 006, India.
authors: Chethan
authors: C
authors: Javarasetty
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005658:Fungi / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010069:Oxadiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011720:Pyrazoles / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D010069:Oxadiazoles; D011720:Pyrazoles; C583463:1,3,4-oxadiazole; C031280:pyrazole
keywords: 1,3,4-Oxadiazoles; Antimicrobial activity; Chloramine-T; Minimum inhibitory concentration (MIC); Pyrazole