scholarly journals Spectroscopic and Biophysical Studies on Chalcones and Schiff Bases Derived from Chromen-2-one and Quinoline-2(1H)-one Derivatives as Antibacterial Agents

2020 ◽  
Vol 32 (7) ◽  
pp. 1719-1727
Author(s):  
Saad H. Alotaibi
Keyword(s):  
13C Nmr ◽  
Dna Cleavage ◽  
Antibacterial Agents ◽  
Spectroscopic Analysis ◽  
Docking Studies ◽  
The Other ◽  
Moderate Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Biophysical Studies

A series of chalcone derivatives and arylidene analogues derived from 3-acetyl coumarin were synthesized. The synthesized compounds were elucidated by spectroscopic analysis such as elemental analysis, infrared, 1H & 13C NMR and mass spectroscopies, and then the synthesized compounds were purified and tested against three bacterial strains. Compound 9c showed high activity against E. coli and P. aeruginosa. Compounds 4 and 6a showed moderate activity against E. coli while compounds 6a, 6b and 9c showed moderate activity against S. aureus. The reference antibiotics were tested against the same bacteria strains in the same conditions and showed that ciprofloxacin have positive activity against P. aeruginosa and S. aureus but it shows negative activity against E. coli while amoxicillin have positive activity against S. aureus and negative activity against E. coli and P. aeruginosa. On the other hand, vancomycin has positive activity against P. aeruginosa but not tested against E. coli and S. aureus. Staph strains were treated with compounds 4 and 7 on DNA fragmentation and DNA cleavage. Docking studies of synthesized compound 9c was determined and the results were compared with ampicillin. Finally, UV and fluorescence analyses of the synthesized compounds (3, 4, 6b, 6c, 6e, 7, 9c and 9e) were also conducted.

Synthesis, Characterization and Biological Evaluation of Some 2-[1-(1,3-Diphenyl-1HPyrazol-4-yl)-meth-(E)-ylidene]indan-1-one Derivatives as Antibacterial Agents

2020 ◽  
Vol 5 (2) ◽  
pp. 127-132
Author(s):  
Uttam B. Chougule ◽  
Hemant V. Chavan ◽  
Savita R. Dhongade
Keyword(s):  
Reaction Time ◽  
Antibacterial Agents ◽  
Spectroscopic Analysis ◽  
Knoevenagel Condensation ◽  
Biological Evaluation ◽  
Bacterial Strains ◽  
Short Reaction Time ◽  
E Coli ◽  
Time Structures ◽  
Substituted 1

A new series of 2-[1-(1,3-diphenyl-1H-pyrazol-4-yl)-meth-(E)-ylidene]-indan-1-one derivatives (5a-l) have been synthesized through through the Knoevenagel condensation of pyrazole carbaldehydes with differently substituted 1-indanone derivatives in the presence of base. A high yielding and solvent-free method was developed for the synthesis of hydrazones from acetophenones under microwave irradiation in a very short reaction time. Structures of the newly synthesized compounds were affirmed by IR, 1H & 13C NMR and mass spectroscopic analysis. The confirmed structures were screened for their antibacterial potency against S. aureus and E. coli bacterial strains. Among the series, compounds 5b, 5c and 5f were evoked as potent antibacterial agents

scholarly journals High-Throughput Screen for Inhibitors of Transglycosylase and/or Transpeptidase Activities of Escherichia coli Penicillin Binding Protein 1b

2004 ◽  
Vol 48 (1) ◽  
pp. 30-40 ◽  
Author(s):  
B. Chandrakala ◽  
Radha K. Shandil ◽  
Upasana Mehra ◽  
Sudha Ravishankar ◽  
Parvinder Kaur ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
Antibacterial Agents ◽  
Binding Protein ◽  
Type A ◽  
The Other ◽  
Penicillin Binding Protein ◽  
E Coli ◽  
Comparison Of The Results ◽  
High Throughput Assay

ABSTRACT Penicillin binding protein (PBP) 1b of Escherichia coli has both transglycosylase and transpeptidase activities, which are attractive targets for the discovery of new antibacterial agents. A high-throughput assay that detects inhibitors of the PBPs was described previously, but it cannot distinguish them from inhibitors of the MraY, MurG, and lipid pyrophosphorylase. We report on a method that distinguishes inhibitors of both activities of the PBPs from those of the other three enzymes. Radioactive peptidoglycan was synthesized by using E. coli membranes. Following termination of the reaction the products were analyzed in three ways. Wheat germ agglutinin (WGA)-coated scintillation proximity assay (SPA) beads were added to one set, and the same beads together with a detergent were added to a second set. Type A polyethylenimine-coated WGA-coated SPA beads were added to a third set. By comparison of the results of assays run in parallel under the first two conditions, inhibitors of the transpeptidase and transglycosylase could be distinguished from inhibitors of the other enzymes, as the inhibitors of the other enzymes showed similar inhibitory concentrations (IC50s) under both conditions but the inhibitors of the PBPs showed insignificant inhibition in the absence of detergent. Furthermore, comparison of the results of assays run under conditions two and three enabled the distinction of transpeptidase inhibitors. Penicillin and other β-lactams showed insignificant inhibition with type A beads compared with that shown with WGA-coated SPA beads plus detergent. However, inhibitors of the other four enzymes (tunicamycin, nisin, bacitracin, and moenomycin) showed similar IC50s under both conditions. We show that the main PBP being measured under these conditions is PBP 1b. This screen can be used to find novel transglycosylase or transpeptidase inhibitors.

scholarly journals Bacterial phagocytosis by macrophages from lipopolysaccharide responder and nonresponder mouse strains

1980 ◽  
Vol 28 (3) ◽  
pp. 762-765
Author(s):  
A Cuffini ◽  
N A Carlone ◽  
G Forni
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
The Other ◽  
Mouse Strains ◽  
Bacterial Strains ◽  
Phagocytic Capacity ◽  
Tumoricidal Activity ◽  
E Coli ◽  
Proteose Peptone ◽  
Lipopolysaccharide Endotoxin

The phagocytic capacity of macrophages from C3H/H3J mice was assessed against lipopolysaccharide-producing (Escherichia coli) and -nonproducing (Staphylococcus aureus) bacteria. Despite their gene-coded unresponsiveness to lipopolysaccharide endotoxin and lymphokines and their defective tumoricidal activity, proteose peptone-induced C3H/HeJ macrophages did not display a defective phagocytic capacity, but rather displayed an enhanced phagocytosis of both bacterial strains compared with macrophages from closely related C3H/HeN mice. Unstimulated peritoneal resident C3H/HeJ macrophages, on the other hand, displayed a normal phagocytic activity toward E. coli and enhanced phagocytosis toward S. aureus.

scholarly journals SYNTHESIS CHARACTERIZATION AND ANTIMICROBIAL ACTIVITIES STUDIES OF N-{2-(4-CHLOROPHENYL) ACETYL} AMINO ALCOHOLS DERIVED FROM α-AMINO ACIDS

2020 ◽  
pp. 11-16
Author(s):  
G. Venkateshappa ◽  
G. Shivaraju ◽  
P. Raghavendra Kumar
Keyword(s):  
Amino Acids ◽  
Amino Alcohols ◽  
Antimicrobial Activities ◽  
Docking Studies ◽  
Moderate Activity ◽  
E Coli ◽  
Synthetic Drugs ◽  
Antimicrobial Studies ◽  
Ft Ir ◽  
Derivatives Of

Amino acids play important roles in organisms to sustain in living state and perform as body constituents, enzymes and antibodies. At insalubrious situations, use of amino acids derivatives as drugs in the maintenance of normal health is better choice than common unnatural synthetic drugs. This is due to the fact that the amino acids derivatives may be more bio-compatible, biodegradable and eliminate easily than others.  In this sense we have made an effort and report herein the synthesis of N-{2-(4-chlorophenyl) acetyl} amino alcohols synthesised by reduction of N-{2-(4-chlorophenyl)acetyl} derivatives of (S)-amino acids such as (S)-phenylalanine, (S)-alanine, (S)-methionine, (S)-leucine, (S)-tryptophan and (S)-proline. These newly synthesized amino acids derivatives were analysed by proton, carbon-13 NMR and FT-IR spectroscopy. The composition of solid derivatives was determined by elemental analysis. Further, antimicrobial activities of these derivatives were assessed on usual bacteria K. aerogenes, E. coli, S. aureus and P. desmolyticum and fungi A. flavus and C. albicans. The compounds were witnessed moderate activity than authorised antibacterial and fungal agents Ciprofloxacin and Fluconazole respectively. The antimicrobial studies also revealed that, these derivatives could be better antifungal agents than antibacterial agents. Finally we compared the experimental results of antimicrobial activities with docking studies.  

scholarly journals β-Lactamase inhibition profile of new amidine-substituted diazabicyclooctanes

2021 ◽  
Vol 17 ◽  
pp. 711-718
Author(s):  
Zafar Iqbal ◽  
Lijuan Zhai ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Second Generation ◽  
Bacterial Species ◽  
The Other ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Mic Value

The diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam-based second generation β-lactamase inhibitors. As part of our efforts, we have synthesized a series of DBO derivatives A1–23 containing amidine substituents at the C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds did not show antibacterial activity when tested alone (MIC >64 mg/L), however, they exhibited a moderate inhibition activity in the presence of meropenem by lowering its MIC values. The compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L to 2 mg/L, and is comparable to avibactam against both E. coli strains with a MIC value of <0.125 mg/L.

scholarly journals 1,4-Naphthoquinone Analogues: Potent Antibacterial Agents and Mode of Action Evaluation

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1437 ◽  
Author(s):  
Palanisamy Ravichandiran ◽  
Sunirmal Sheet ◽  
Dhanraj Premnath ◽  
Ae Rhan Kim ◽  
Dong Jin Yoo
Keyword(s):  
Antibacterial Activity ◽  
Mode Of Action ◽  
Bacterial Infections ◽  
Antibacterial Agents ◽  
Annexin V ◽  
Ros Generation ◽  
Redox Potentials ◽  
Bacterial Strains ◽  
E Coli ◽  
New Class

1,4-Naphthoquinones have antibacterial activity and are a promising new class of compound that can be used to treat bacterial infections. The goal was to improve effective antibacterial agents; therefore, we synthesized a new class of naphthoquinone hybrids, which contain phenylamino-phenylthio moieties as significant counterparts. Compound 4 was modified as a substituted aryl amide moiety, which enhanced the antibacterial activity of earlier compounds 3 and 4. In this study, five bacterial strains Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae) were used to evaluate the antibacterial potency of synthesized naphthoquinones using the minimal inhibitory concentration (MIC) method. Most of the studied naphthoquinones demonstrated major antibacterial activity with a MIC of 15.6 µg/mL–500 µg/mL. Selected compounds (5a, 5f and 5x) were studied for the mode of action, using intracellular ROS generation, determination of apoptosis by the Annexin V-FITC/PI assay, a bactericidal kinetic study and in silico molecular modelling. Additionally, the redox potentials of the specified compounds were confirmed by cyclic voltammetry (CV).

scholarly journals Phenolic compounds and antioxidant, antimicrobial and antimycobacterial activities of Serjania erecta Radlk. (Sapindaceae)

2013 ◽  
Vol 49 (4) ◽  
pp. 775-782 ◽  
Author(s):  
Claudia Andréa Lima Cardoso ◽  
Roberta Gomes Coelho ◽  
Neli Kika Honda ◽  
Arnildo Pott ◽  
Fernando Rogério Pavan ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Ethanolic Extract ◽  
Chemical Study ◽  
The Other ◽  
Moderate Activity ◽  
E Coli ◽  
Ethanolic Extracts ◽  
Leaves And Roots ◽  
Microtiter Assay

Serjania erecta Radlk.(Sapindaceae) is a medicinal plant traditionally used in Brazil. We assayed the ethanolic extract of leaves and roots against seven microorganisms. The REMA (Resazurin Microtiter Assay) assay was used to measure the biological activity in vitro against Mycobacterium tuberculosis and our results showed moderate activity of the ethanolic extract. On the other hand S. aureus, P. aeruginosa, S. setubal, C. albicans, S. cerevisiae and E. coli revealed that the leaves and roots of S. erecta inhibited the growth of all microorganisms. The ethanolic extracts of leaves and roots showed low values of antioxidant activities. The ethanolic extracts of leaves and roots were analyzed by chromatographic and spectrometric methods. (-)-Epicatechin, kaempferol aglycone and five glycoside derivates were isolated: kaempferol-3-O-α-L-rhamnopyranoside, kaempferol-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside from the roots and kaempferol, kaempferol 3,7-di-O-α-L-rhamnopyranoside, vitexin, isovitexin and (-)-epicatechin in the leaves. This is the first chemical study reported in the literature about this specie.

Synthesis and Characterization of Novel 1,3,5-Thiadiazine Derivatives Integrated with Quinoline Moiety as Potent Antimicrobial Agents

2020 ◽  
Vol 5 (2) ◽  
pp. 149-155
Author(s):  
M. Idrees ◽  
Naqui J. Siddiqui ◽  
Yogita G. Bodkhe ◽  
Satish Kola
Keyword(s):  
13C Nmr ◽  
Mass Spectra ◽  
Antimicrobial Agents ◽  
Synthesis And Characterization ◽  
Pathogenic Microorganism ◽  
Bacterial Strains ◽  
Gram Negative ◽  
E Coli

An expeditious synthesis of series of novel 1,3,5-thiadiazine (5a-f) and (6a-f) derivatives have been described. These compounds were synthesized by reaction of 1-(N-((6-methyl-2-(p-tolyloxy)quinoline- 3-yl)methylene)carbamimidoyl)-3-arylthiourea (3a-b) derivatives with N-aryl isocyanodichloride (4a-c) in chloroform followed by basification with dilute NH4OH to give the target compounds 5a-f; which were acetylated further to afford six novel 1,3,5-thiadiazin-3-(6H)-yl)ethanone (6a-f) derivatives. Synthesis of intermediate compounds 3a-b was obtained by reacting 6-methyl-2-(p-tolyloxy)quinoline-3- carbaldehyde (2a) and 1-carbamimidoyl-3-aryllthiourea (1a-b) in chloroform. Structures of compounds 5a-f and 6a-f were established by FTIR, 1H & 13C NMR, mass spectra and further supported by elemental analysis. All synthesized compounds were investigated for their in vitro antimicrobial screening against a panel of pathogenic microorganism comprising S. aureus as Gram positive while E. coli, P. vulgaris, S. typhi as Gram-negative bacterial strains.

scholarly journals Study of the mechanism of antibacterial action of 1,4-di- and 1,4,5-trisubstituted 1Н-1,2,3-triazoles by molecular modeling

2020 ◽  
pp. 48-63
Author(s):  
Cyril M. Verbilo ◽  
Alexander V. Zuraev ◽  
Yuri V. Grigoriev ◽  
Vladislav A. Budevich ◽  
Oleg A. Ivashkevich
Keyword(s):  
Molecular Modeling ◽  
Binding Site ◽  
Antibacterial Agents ◽  
Docking Studies ◽  
Antibacterial Action ◽  
Binding Mechanism ◽  
Target Proteins ◽  
E Coli ◽  
Experimental Activity ◽  
Binding Models

The target for antibacterial action of 1,4-di- and 1,4,5-trisubstituted 1H-1,2,3-triazoles against E. coli ATCC 25922 and S. aureus ATCC 6538 was proposed. Structures of target proteins and investigated triazoles were built using molecular modeling. Binding mechanism was suggested according to conducted docking studies. Suggested binding models and affinity for a binding site of 1,4-disubstituted 1H-1,2,3-triazoles correlated with their experimental activity. Further functionalization directions for continuation of a search for a novel effective antibacterial agents were discovered.

scholarly journals Identification and Antibacterial Resistance of Bacteria Isolated from Poultry

2012 ◽  
Vol 61 (4) ◽  
pp. 323-326 ◽  
Author(s):  
FADI. E. EL-RAMI ◽  
FAWWAK. T. SLEIMAN ◽  
LEXANDER. M. ABDELNOOR
Keyword(s):  
Antibacterial Agents ◽  
Antibacterial Resistance ◽  
Bacterial Strains ◽  
Growth Promoters ◽  
E Coli ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Antibiotic Growth Promoters ◽  
Food Borne Infections ◽  
Potential Food

Food-borne infections are among the prominent health hazards. Antibacterial agents (ABA) are usually administered to poultry in Lebanon as antibiotic growth promoters (AGP), which might lead to the dissemination of resistant bacterial strains. The aims of this study were to isolate potential food borne pathogens from poultry and investigate an association between AGP usage and antibacterial resistance (ABR). Isolates were obtained from the culture of cloacae swabs and identified. Escherichia coli was the predominant isolate. There was a significant association between the use of tetracycline and gentamicin as AGP and the number of E. coli isolates resistant to these ABA.

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