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 Synthesis and Antimicrobial Evaluations of Sulfur Inserted Fluoro-Benzimidazoles

2021 ◽  
Vol 33 (7) ◽  
pp. 1525-1529
Author(s):  
Parmesh Kumar Dwivedi ◽  
Devdutt Chaturvedi
Keyword(s):  
Antimicrobial Agents ◽  
Bacterial Strains ◽  
Substituted Anilines ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
New Compounds ◽  
Derivatives Of ◽  
Multiple Step

A new series of fluorinated sulfur inserted benzimidazole analogues Za-i were synthesized and characterized. The new compounds were screened for their antimicrobial and antioxidant potential. The synthesized compounds were obtained by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol X. The compounds Ya-i prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF. Finally, the compound X was reacted with different derivatives of 2-chloro-N-phenylacetamide resulting in formation of titled compounds Za-i. The synthesized compounds (Za-Zi) were characterized by spectral analysis viz.1H & 13C NMR, mass spectra, elemental analysis and IR. The in vitro antimicrobial potential against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans) was recorded for the obtained compounds. Some of the compounds exhibited encouraging results (in MIC) against Gram-positive and Gram-negative bacterial strains. These studies thus suggest that the designed sulfur inserted fluoro-benzimidazoles scaffold may serve as new promising template for further amplification as antimicrobial agents.

scholarly journals In Vitro, Controlling the Establishment of Xanthomonas Campestris with different Bacterial Bioagents

2016 ◽  
Vol 29 (1) ◽  
pp. 37-40
Author(s):  
Amna Ali ◽  
M Saleem Haider ◽  
Sobia Mushtaq ◽  
Ibatsam Khokhar ◽  
Irum Mukhtar ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Diffusion Technique

The antimicrobial agents of bacteria isolated from different rhizosphere of fruits and vegetables soil in Lahore. Of ten species, five were gram-negative (Escherichia coli, Pseudomonas fluorescence, Klebsiella pneumoniae, Salmonella typhii, Brachybacterium faecium); other five were gram positive and identified as Bacillus farraginis, Kurthia gibsonii, Aureobacterium liquefaciens, Curtobacterium albidum, Micrococcus lylae. The antagonistic potential of bacterial strains was assessed by the well diffusion technique and results indicating varying degree of biocontrol activity against pathogenic strain of X. campestris. Out of ten bacterial species, E. coli (gram negative) and C. albidum (gram positive) showed a high prevalence of resistance with reduction of 4.2cm and 4.1cm zone diameter respectively. The minimum inhibitory volume (MIV) to two bio-agents was determined for X. campestris from range 10-100 ?L. E. coli (volume required to inhibit < 20 ?L) and C. albidum (volume required to inhibit < 40 ?L) exhibited good activity against pathogen. These results provide information on the prevalence of resistant bacterial strains with the MIV of organisms and indicate the possibility of using these bacterial species as bio-agent against X. campestris.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 37-40

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

scholarly journals Investigating In Vitro Antibacterial Activities of Medicinal Plants Having Folkloric Repute in Ethiopian Traditional Medicine

2019 ◽  
Vol 24 ◽  
pp. 2515690X1988627 ◽  
Author(s):  
Mekonnen Sisay ◽  
Negussie Bussa ◽  
Tigist Gashaw ◽  
Getnet Mengistu
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Antimicrobial Agents ◽  
Bacterial Isolates ◽  
Zone Of Inhibition ◽  
Traditional Use ◽  
Gram Negative ◽  
E Coli ◽  
Slow Development

Medicinal plants are targeted in the search for new antimicrobial agents. Nowadays, there is an alarmingly increasing antimicrobial resistance to available agents with a very slow development of new antimicrobials. It is, therefore, necessary to extensively search for new agents based on the traditional use of herbal medicines as potential source. The antibacterial activity of 80% methanol extracts of the leaves of Verbena officinalis (Vo-80ME), Myrtus communis (Mc-80ME), and Melilotus elegans (Me-80ME) was tested against 6 bacterial isolates using agar well diffusion technique. In each extract, 3 concentrations of 10, 20, and 40 mg/well were tested for each bacterium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Vo-80ME and Mc-80ME exhibited promising antibacterial activity against Staphylococcus aureus with the highest zone of inhibition being 18.67 and 26.16 mm, respectively at concentration of 40 mg/well. Regarding gram-negative bacteria, Vo-80ME exhibited an appreciable activity against Escherichia coli and Salmonella typhi. Mc-80ME displayed remarkable activity against all isolates including Pseudomonas aeruginosa with the maximum zone of inhibition being 22.83 mm. Me-80ME exhibited better antibacterial activity against E coli, but its secondary metabolites had little or no activity against other gram-negative isolates. The MIC values of Vo-80ME ranged from 0.16 to 4.00 mg/mL. The lowest MIC was observed in Mc-80ME, with the value being 0.032 mg/mL. Mc-80ME had bactericidal activity against all tested bacterial isolates. Mc-80ME showed remarkable zone of inhibitions in all tested bacterial isolates. Besides, Vo-80ME showed good antibacterial activity against S aureus, E coli, and S typhi. Conversely, Me-80ME has shown good activity against E coli only. Generally, M communis L and V officinalis have good MIC and MBC results.

scholarly journals In Vitro Activity of Newer and Conventional Antimicrobial Agents, Including Fosfomycin and Colistin, against Selected Gram-Negative Bacilli in Kuwait

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
The Other ◽  
In Vitro Activity ◽  
Limited Data ◽  
Gram Negative ◽  
E Coli ◽  
Microbroth Dilution

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.

Synthesis and Evaluation of Novel Fluorobenzimidazole Derivatives as Antibacterial and Antifungal Agents

2019 ◽  
Vol 4 (4) ◽  
pp. 209-215
Author(s):  
D. Joshi ◽  
R. Narigara ◽  
G. Jani ◽  
K. Parikh
Keyword(s):  
Bacterial Strains ◽  
Compound I ◽  
Substituted Anilines ◽  
Gram Negative ◽  
E Coli ◽  
New Class ◽  
Antibacterial And Antifungal ◽  
Derivatives Of ◽  
Multiple Step

A new class of fluorobenzimidazole derivatives (IIIa-j)was synthesized to investigate their antimicrobial potential. All the compounds were prepared by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol (I). The compound I was further reacted with different derivatives of 2-chloro-N-phenylacetamide (IIa-j) prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF (solvent); resulting in formation of fluorobenzimidazoles IIIa-j. The compounds IIIa-j were characterized by spectral analysis viz. 1H NMR, 13C NMR, mass spectra, elemental analysis and IR. All these compounds were screened in vitro for their antimicrobial activity against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans). Some of the compounds exhibited promising results (in MIC) against Gram-negative bacterial strains.

scholarly journals Synthesis of sulfonamides bearing 1,3,5-triarylpyrazoline and 4-thiazolidinone moieties as novel antimicrobial agents

2020 ◽  
Vol 85 (2) ◽  
pp. 155-162
Author(s):  
Thi-Dan Thach ◽  
Thi Le ◽  
Thien-Annguyen Nguyen ◽  
Chi-Hien Dang ◽  
Van-Su Dang ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Significant Inhibition ◽  
Mercaptoacetic Acid ◽  
Bacterial Strains ◽  
Reference Drug ◽  
E Coli ◽  
Yeast Strains ◽  
Microbial Strains

Two series of sulfonamides were synthesized from 4-hydrazinylbenzenesulfonamide as the key starting material. 1,3,5-Triarylpyrazoline sulfonamides (2a?i) were obtained by cyclocondensation of various chalcones in 53? ?64 % yields, while 4-thiazolidinone derivatives (4a?e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydrazones in 43?62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a?c and 2e?h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good antifungal activity against A. niger (MIC value at 12.5 ?g mL-1) over the reference drug.

scholarly journals Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria

2016 ◽  
Vol 14 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Lucia Pirvu ◽  
Isabela Nicorescu ◽  
Cristina Hlevca ◽  
Bujor Albu ◽  
Valentin Nicorescu
Keyword(s):  
Synergistic Effects ◽  
Herbal Medicines ◽  
Antimicrobial Properties ◽  
Inhibition Zone ◽  
In Vitro Activity ◽  
Bacterial Strains ◽  
Gram Negative ◽  
E Coli ◽  
Effective Source

AbstractEpilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE) were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1) (S. epidermidis ATCC 12228) to very resistant (E. coli strains), E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl) derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.

scholarly journals Design, Synthesis, and Antibacterial Screening of Some Novel Heteroaryl-Based Ciprofloxacin Derivatives as DNA Gyrase and Topoisomerase IV Inhibitors

2021 ◽  
Vol 14 (5) ◽  
pp. 399
Author(s):  
Lamya H. Al-Wahaibi ◽  
Amer A. Amer ◽  
Adel A. Marzouk ◽  
Hesham A.M. Gomaa ◽  
Bahaa G. M. Youssif ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dna Gyrase ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Screening ◽  
Ic50 Values

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).

scholarly journals Antibacterial Activities and Characterization of Novel Inhibitors of LpxC

2002 ◽  
Vol 46 (6) ◽  
pp. 1793-1799 ◽  
Author(s):  
John M. Clements ◽  
Fanny Coignard ◽  
Ian Johnson ◽  
Stephen Chandler ◽  
Shilpa Palan ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Lipid A ◽  
Antibacterial Activities ◽  
Vitro Assay ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Target ◽  
Derivatives Of

ABSTRACT Lipid A is the hydrophobic anchor of lipopolysaccharide (LPS) and forms the major lipid component of the outer monolayer of the outer membrane of gram-negative bacteria. Lipid A is required for bacterial growth and virulence, and inhibition of its biosynthesis is lethal to bacteria. UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is a metalloenzyme that catalyzes the second step in the biosynthesis of lipid A. Inhibitors of LpxC have previously been shown to have antibiotic activities. We have screened a metalloenzyme inhibitor library for antibacterial activities against an Escherichia coli strain with reduced LpxC activity. From this screen, a series of sulfonamide derivatives of the α-(R)-amino hydroxamic acids, exemplified by BB-78484 and BB-78485, have been identified as having potent inhibitory activities against LpxC in an in vitro assay. Leads from this series showed gram-negative selective activities against members of the Enterobacteriaceae, Serratia marcescens, Morganella morganii, Haemophilus influenzae, Moraxella catarrhalis, and Burkholderia cepacia. BB-78484 was bactericidal against E. coli, achieving 3-log killing in 4 h at a concentration 4 times above the MIC, as would be predicted for an inhibitor of lipid A biosynthesis. E. coli mutants with decreased susceptibility to BB-78484 were selected. Analysis of these mutants revealed that resistance arose as a consequence of mutations in the fabZ or lpxC genes. These data confirm the antibacterial target of BB-78484 and BB-78485 and validate LpxC as a target for gram-negative selective antibacterials.

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