Synthesis, Cytotoxicity and Antimicrobial Evaluation of Some New 2-Aryl,5-Substituted 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles

Abstract

The synthesis of 2-(5-methyl-2-nitrophenyl)-5-(substituted)-1,3,4-oxadiazoles (5a-e) and thiadiazoles (6a-e) was carried out by refluxing of N-(5-methyl-2-nitrobenzoyl)-2-substituted carbohydrazide with phosphorous oxychloride and Lawesson's reagent respectively. The N-(5-methyl-2-nitrobenzoyl)-2-substituted carbohydrazides was synthesized by treating 2(5-methyl-2-nitrobenzohydrazide) with various aryl acids in the presence of HATU and DIPEA. Compounds 6a, 5c and 5d exhibited significant cytotoxic properties when compared to standard podophyllotoxin. Further, the compounds were also studied for their antibacterial activities.

Microwave and Conventional Study of Coumarin-Oxadiazole Adducts and their Anti-Microbial Evaluation

“…Yield: 78%; mp 235°C; IR (ATR, cm -1 ): 2919 (-C-H stretching methylene group), 1739 (>C=O stretching esteric carbonyl group), 1702 (>C=O stretching lactone carbonyl group), 1482, 1351 (C-NO 2 stretching), 1361 (C-N stretching carbon nitrogen linkage), 1271, 1021 (C-O-C stretching oxadiazole ring), 1286 (C-O stretching ester); 1 18, 174.27, 170.35, 167.21, 162.96, 148.18, 145.32, 142.65, 139.43, 136.21, 132.63, 128.16, 126. 38, 166.13, 163.46, 162.35, 161.67, 140.31, 134.18, 127.41, 125.20, 124.83, 123.15, 122.69, 120.45, 118.34, 81.15, 37.35, 28.17; MS: m/z 395 (M + ); Elemental analysis of C 20 H 14 N 2 O 5 S: Calculated= C, 60.91; H, 3.58;N,7.10;O,20.28;S,8.13 and Found= C,60.85;H,3.64;N,7.13;O,20.24;S,8.08. 2H-chromen-4-yl 2-((5-(m-tolyl)-1,3,4oxadiazol-2-yl) 11, 173.63, 171.48, 163.45, 161.18, 141.47, 139.51, 135.48, 132.61, 130.35, 129.13, 127.67, 125.11, 124.10, 122.45, 119.21, 118.67, 95.82, 35.30, 29.18; MS: m/z 395 (M + ); Elemental analysis of C 20 H 14 N 2 O 5 S: Calculated= C, 60.91; H, 3.58;N,7.10;O,20.28;S,8.13 and Found= C,60.93;H,3.57;N,7.08;O,20.31;S,8.15.…”

“…Antifungal and antibacterial evaluations were carried out by micro dilution/broth titer method. 8 The stock solution (DMSO: 1000 μg/ml) for each compound was prepared and antimicrobial assay was carried out by serial dilution and preparing the sets consecutively from 1000, 500, 200, 100, 50, 25 and 12.5 µg ml -1 . The tubes along with the control were then kept for incubation at 37°C for 24 h. Suspensions were further inoculated on an appropriate media and growth was noted after 48 h. The obtained re-sults (MIC) in μg/ml was noted by observing the highest dilutions (low turbidity) were recorded and compared with the MIC value of standard drugs using ampicillin for antibacterial activity and griseofulvin for antifungal activity.…”

Novel Substituted Indazoles towards Potential Antimicrobial Agents

“…Very recently our group reported the synthesis and anticancer activity of N-methyl-3-arylindazole derivatives using Pd catalyst. 23 In continuation to our efforts in developing structurally diverse heterocyclic compounds as antimicrobial agents [24][25][26][27] herein, we report the antimicrobial activities of some N-methyl-3-arylindazoles (5a-5j).…”

1,3,4-Thiadiazole Scaffold: As Anti-Epileptic Agents

“…The molecular structure of a compound is responsible for various pharmacological activities, and mostly heterocyclic moieties have diverse activities. This scaffold (Figure 1A) derivatives possess a wide range of biological activities such as anticancer/antitumor (Janowska et al, 2020;Cevik et al, 2020;Gomha et al, 2017;Flefel et al, 2017;Ningegowda et al, 2017), anticonvulsant (Khatoon et al, 2018;Bhandari et al, 2008;Jatav et al, 2008;Foromadi et al, 2007;Almasirad et al, 2007;Dawood et al, 2006;Dogan et al, 2002;Varvaresou et al, 1998;Khazi et al, 1996;Stillings et al, 1986;Chapleo et al, 1986), antidiabetic (Vaishnav et al, 2017;Datar and Deokule, 2014;Thrilochana et al, 2014), anti-inflammatory (Cristina et al, 2018;Schenone et al, 2006), antidepressant (Can et al, 2012), antihypertensive (Samel and Pai, 2010), antiviral (Serban et al, 2020;Brai et al, 2019), antimicrobial (Gowda et al, 2020;Merugu et al, 2020;Mutchu et al, 2019;Sekhar et al, 2018;Joseph et al, 2015), antioxidant (Yakan, 2021;Gowda et al, 2020), anti-leishmanial (Tahghighi and Babalouei, 2017;Sadat-Ebrahimi et al, 2019), and neuroprotective (Skrzypeka et al, 2021). The biological activities of several synthesized derivatives of 1,3,4-thiadiazole are based on assumptions like "the N-C-Smoiety's presence and strong aromaticity of the ring, which is responsible for providing low toxicity and great in vivo st...…”