Synthesis of pyrazole-based Schiff bases of Chitosan: Evaluation of antimicrobial activity

Anush, S.M.; Vishalakshi, B.; Kalluraya, Balakrishna; Manju, N.

doi:10.1016/j.ijbiomac.2018.07.129

Cited by 99 publications

(39 citation statements)

References 21 publications

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“…To a mixture of 3-methyl-5-aryloxy-1-phenyl-1H-pyrazole-4carbaldehyde (1 a-c) [21][22] (0.01 mol) and acetyl thiophene (2) (0.01 mol) in 25 mL of ethanol, pottasium hydroxide (0.5g, 0.01 mol) in 5 mL ethanol was added drop wise under ice bath, and the mixture was stirred for 4 hours. After the completion of the reaction (monitored by TLC), the solid product separated was filtered, washed with water, dried and recrystallized from ethanol: dimethylformamide mixture.…”

Section: General Procedures For the Synthesis 3-(3-methyl-5aryloxy-1-pmentioning

confidence: 99%

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et al. 2019

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In this paper, we describe a simple catalyst-free protocol for the synthesis of thiazole, thiazolone integrated pyrazole derivatives, under ultra-sonication technique. Thiazolone derivatives (5a, 5e, 5i, 5d, 5h, 5l)were derived from [3+2] cyclocondensation reaction between carbothioamide pyrazoline (4a-c) as S-N bi-nucleophile with DMAD/DEAD. The target molecules (5b, 5f, 5j,5c, 5g, 5k)were synthesized by the reaction of (4a-c) with the substituted bromoethanone. Formation of the products was confirmed by FT-IR, 1 H-NMR, 13 C-NMR, LC-MS analysis. Docking studies were carried out against the antimicrobial target (Acinetobacterbaumannii penicillin) to know the interaction of the molecules (ligands) with the docked target. Among the docked compounds thiazolone derivative (5d) showed theminimum binding energy of-9.08 kJ/mol with ligand efficiency of-0.23. All the synthesized compounds were examined primarily for their in-vitro antibacterial and antioxidant activity (IC 50). Compound (5g)(18±0.0) and (5d)(19.5±0.5) showed significant bacterial inhibition against E.coli and S.aureus. Compound (5k) (16.57) showed substantially DPPH free radical inhibition activity as compared to the reference drug Ascorbic acid.

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Section: General Procedures For the Synthesis 3-(3-methyl-5aryloxy-1-pmentioning

confidence: 99%

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et al. 2019

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“…Schiff bases are important compounds in chemistry and biochemistry due to their flexibility (Mayans et al, 2018;Pramanik et al, 2018), easy preparation (Erxleben, 2018;ISSN 2053ISSN -2296 # 2020 International Union of Crystallography Ganguly et al, 2014), exceptional chelating ability (Malik et al, 2018;Vardhan et al, 2015) and to their broad spectrum of biological and pharmaceutical activities, such as antimicrobial (Anush et al, 2018;Unver & Bektas, 2018;Bharathi et al, 2018;Carreñ o et al, 2018), anti-inflammatory (Venkatesan et al, 2018;Farag et al, 2017;Bano et al, 2017;Khayyat et al, 2015) and anticancer properties (Unver & Bektas, 2018;Santhosh Kumar et al, 2018;Kalaiarasi et al, 2018;Ariyaeifar et al, 2018). Thus, the chemistry of Schiff bases has always been a promising field of research.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, crystal structures, antiproliferative activities and reverse docking studies of eight novel Schiff bases derived from benzil

et al. 2020

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Eight novel Schiff bases derived from benzil dihydrazone (BDH) or benzil monohydrazone (BMH) and four fused-ring carbonyl compounds (3-formylindole, FI; 3-acetylindole, AI; 3-formyl-1-methylindole, MFI; 1-formylnaphthalene, FN) were synthesized and characterized by elemental analysis, ESI–QTOF–MS, 1H and 13C NMR spectroscopy, as well as single-crystal X-ray diffraction. They are (1Z,2Z)-1,2-bis{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFI), C32H24N6, (1Z,2Z)-1,2-bis{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethane (BDHAI), C34H28N6, (1Z,2Z)-1,2-bis{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BMHMFI) acetonitrile hemisolvate, C34H28N6·0.5CH3CN, (1Z,2Z)-1,2-bis{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFN), C36H26N4, (Z)-2-{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFI), C23H17N3O, (Z)-2-{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethanone (BMHAI), C24H19N3O, (Z)-2-{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHMFI), C24H19N3O, and (Z)-2-{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFN) C25H18N2O. Moreover, the in vitro cytotoxicity of the eight title compounds was evaluated against two tumour cell lines (A549 human lung cancer and 4T1 mouse breast cancer) and two normal cell lines (MRC-5 normal lung cells and NIH 3T3 fibroblasts) by MTT assay. The results indicate that four (BDHMFI, BDHFN, BMHMFI and BMHFN) are inactive and the other four (BDHFI, BDHAI, BMHFI and BMHAI) show severe toxicities against human A549 and mouse 4T1 cells, similar to the standard cisplatin. All the compounds exhibited weaker cytotoxicity against normal cells than cancer cells. The Swiss Target Prediction web server was applied for the prediction of protein targets. After analyzing the differences in frequency hits between these active and inactive Schiff bases, 18 probable targets were selected for reverse docking with the Surflex-dock function in SYBYL-X 2.0 software. Three target proteins, i.e. human ether-á-go-go-related (hERG) potassium channel, the inhibitor of apoptosis protein 3 and serine/threonine-protein kinase PIM1, were chosen as the targets. Finally, the ligand-based structure–activity relationships were analyzed based on the putative protein target (hERG) docking results, which will be used to design and synthesize novel hERG ion channel inhibitors.

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“…Additionally Schiff (Liu and Hamon, 2019;Alpaslan et al, 2019) and Mannich base (Kulkarni et al, 2017;Mohanvel et al, 2019) exhibited excellent pharmacological properties. Conversely, isoxazoles (Kumar et al, 2015;Tatee et al, 1987), pyrazoles (Alagarsamy and Saravanan, 2013;Selvam et al, 2014;Anush et al, 2018) & pyrimidines (Hanna, 2012;Kuppast and Fahmy, 2016) have gained signi icance due to their associated pharmacological and physiological potencies. Hence, in the present work, an effort has been made to prepare a series of novel isoxazole/ pyrazole/ pyrimidine nucleus substituted 5-nitroisatin as a potent anti-epileptic agent.…”

Section: Introductionmentioning

confidence: 99%

Design, Synthesis, Characterisation & Anticonvulsant Activities of Novel Heterocyclic Substituted Isatin Derivatives

Lahari¹,

Sundararajan²

2020

ijrps

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Twelve new isoxazole/pyrazole/pyrimidine substituted 5-nitrosation analogues were designed according to the requirements of the anticonvulsant drugs pharmacophore model and synthesised from indole-2,3-dione. Entire prepared compounds chemical structures were established from its IR, proton-NMR, Mass spectrum & microanalysis data. Anticonvulsant potency of final isatin analogues was assessed by MES technique & sc PTZ technique. Besides rotarod test was used to assess the neurotoxicity of all potent title analogues. Title compounds exhibited a varying degree of anticonvulsant potency ranging from mild to good. In the present study, it was concluded that pyrazole derivatives exhibited higher anti-epileptic activity than isoxazole derivatives. However, pyrimidine analogues displayed inferior activity than isoxazole analogues. 4-(2-(4-(1-((Dimethylamino)methyl)-5-nitro-2-oxindole-3-ylideneamino)phenyl) hydrazone)-1-(4-chlorophenyl)-3-amino-1H-pyrazole-5(4H)-one 7c was established as the most active analog of this series. Hence this derivative can act as a pilot molecule for further progress of new effective anticonvulsant drugs.

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Synthesis of pyrazole-based Schiff bases of Chitosan: Evaluation of antimicrobial activity

Cited by 99 publications

References 21 publications

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Synthesis, crystal structures, antiproliferative activities and reverse docking studies of eight novel Schiff bases derived from benzil

Design, Synthesis, Characterisation & Anticonvulsant Activities of Novel Heterocyclic Substituted Isatin Derivatives

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