scholarly journals Synthesis, Characterisation and Biological Evaluation of Substituted 4- ((1H-Benzo[d]Imidazol-2-YL) Methoxy) Coumarin Derivatives as Antimicrobial Agents

2019 ◽  
Vol 7 (02) ◽  
pp. 01-08
Author(s):  
Harpreet Kaur ◽  
Baljeet Singh

A series of coumarin-benzimidazole derivatives i.e. 4-((1H-Benzo[d]imidazol-2- yl)methoxy)coumarin derivatives (7a-j) was synthesized by reacting appropriate starting materials and evaluated for its in vitro antimicrobial activity. The newly synthesized compounds have been characterized on the basis of elemental analyses, spectroscopic techniques (FT-IR). Antimicrobial studies of these compounds were performed against the both the Gram positive, MRSA (Staphylococcus aureus, Bacillus subtilis) as well as Gram negative (Escherichia coli) bacteria. The activity was investigated by using both Agar well diffusion as well as MIC assay. All the compounds were show significant bactericidal activity against all the pathogenic strains in comparison to Ciprofloxacin, a broad spectrum antibiotic against Gram positive and Gram negative bacteria. Most of the synthesized derivatives appeared as excellent antimicrobial agents as compared to standard drug Ciprofloxacin. Compound 7b was found to be the most active antibacterial agent against Gram positive as well as Gram negative bacteria.

Author(s):  
Pooja Pisal ◽  
Meenakshi Deodhar ◽  
Amol Kale ◽  
Ganesh Nigade ◽  
Smita Pawar

Objective: A new series 2-phenyl-3-(substituted benzo[d] thiazol-2-ylamino)-quinazoline-4(3H)-one was prepared by the fusion method by reacting 2-phenyl benzoxazine with 2-hydrazino benzothiazole and it was evaluated for their antimicrobial activity against gram positive, gram negative bacteria and fungi.Methods: Titled compounds were synthesized by fusion reactions. These compounds were evaluated by in vitro antibacterial and antifungal activity using the minimum inhibitory concentration and zone of inhibition methods. The synthesized compounds were characterized with the help of infrared, NMR and mass spectral studies. The benzothiazole moiety and the quinazoline ring have previously shown DNA gyrase inhibition and target related antibacterial activity. Thus, molecular docking studies of synthesized compounds were carried out (PDB: 3G75) to study the possible interaction of compounds with the target. The batch grid docking was performed to determine the probable.Results: These compounds showed significant activity against gram positive and gram negative bacteria as well against the fungi. The compound A5 was found to be active against B. subtilis, P aeruginosa and C. albican at 12.5 µg/ml MIC. The compound A3 was found to be active against all microbial strains selected at 25 and 12.5 µg/ml MIC.Conclusion: Though the relationship between the activities shown by these compounds in, the antimicrobial study is still to be established, the docking studies conducted found to be consistent with antimicrobial results. Thus the results indicate that the designed structure can be a potential lead as an antimicrobial agent.


2009 ◽  
Vol 6 (s1) ◽  
pp. S342-S346 ◽  
Author(s):  
Y. S. Chhonker ◽  
B. Veenu ◽  
S. R. Hasim ◽  
Niranjan Kaushik ◽  
Devendra Kumar ◽  
...  

Some new 2- phenyl benzimidazole derivatives were synthesised by cyclocondensation with appropriate reagents. The compounds synthesised were identified by1H NMR, FAB Mass and FT-IR spectroscopic techniques. All compounds studied in this work were screened for theirin vitroantimicrobial activities against the standard strains:Staphylococcus aureusATCC - 25923, ATCC - 441 andBacillus subtilisATCC- 6633 as gram positive,Escherichia coliATCC - 11775 andPseudomonas aeruginosaATCC 10145 as gram negative bacteria. Some of the compounds inhibited the growth of gram-positive bacteria (B. subtilisandS. aureus) at MIC values between 25 and 200 mg/mL. Some of the compounds exhibit antimicrobial activity against gram negative bacteria (E. coliandP. Aeruginosa) MIC values between 25 and 200 mg/mL.


Author(s):  
Zohor Mohammad Mahdi Alzhrani ◽  
Mohammad Mahboob Alam ◽  
Syed Nazreen

Background: The frequent uses of antimicrobial agents to treat infections in diabetic patients make them more drug resistance than non diabetic patients which accounts for higher mortality rate of diabetic patients. Therefore, it is a necessity today to synthesize new drugs with dual mode of action as antidiabetic and antibacterial agents. In the present work, new derivatives containing thiazolidinedione and 1,3,4-oxadiaozle have been synthesized and screened for PPAR-γ and antibacterial activities. Methods: Compound 5-12 have been synthesized from 2-methoxy benzaldehyde and thiazolidinedione and characterized using different spectroscopic techniques such as IR, NMR and mass spectrometry. These compounds were tested for in vitro PPAR-γ transactivation, PPAR-γ gene expression and antibacterial activities. Finally molecular docking was carried out to see the binding interactions of molecules with the target protein. Results: All the compounds follow Lipinski rule suggesting the synthesized derivatives have good drug likeness properties. Compound 11 and 12 exhibited promising PPAR-γ transactivation with 73.69% and 76.50%, respectively as well as showed significant antibacterial activity with comparable MIC of 3.12 μg/disc to standard drug amoxicillin. The docking result was found to be in consistent with the in vitro PPAR-γ transactivation results. Conclusion: Compounds 11 and 12 can be further investigated as lead molecules for the development of new and effective antidiabetic and antibacterial agents.


New compounds containing 4-thiazolidinone pharmacophore 5(a) and (5b) have been synthesized. The chemical structures of the intermediate and final compounds were characterized and confirmed by using FT-IR and 1H-NMR spectroscopy. All final compounds were tested against gram-positive and gram-negative bacteria using a well-diffusion technique for their ability as antimicrobial agents. The tested compounds 5a and 5b showed variable and modest antibacterial activity against gram-negative bacteria and gram-positive bacteria. Molecular docking simulations were studied to understand the molecular core. The results were achieved by docking, the most active compounds into the active site of protein of the bacteria which completely accorded with in vitro results.


Chemotherapy ◽  
2017 ◽  
Vol 62 (3) ◽  
pp. 194-198 ◽  
Author(s):  
Socorro Leyva-Ramos ◽  
Denisse de Loera ◽  
Jaime Cardoso-Ortiz

Background: Fluoroquinolones are widely prescribed synthetic antimicrobial agents. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome; the irreversible DNA damage eventually causes the killing of bacteria. Thorough knowledge of the structure-activity relationship of quinolones is essential for the development of new drugs with improved activity against resistant strains. Methods: The compounds were screened for their antibacterial activity against 4 representing strains using the Kirby-Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was determined by measuring the diameter of the inhibition zone using concentrations between 250 and 0.004 μg/mL. Results: MIC of derivatives 2, 3, and 4 showed potent antimicrobial activity against gram-positive and gram-negative bacteria. The effective concentrations were 0.860 μg/mL or lower. MIC for compounds 5-11 were between 120 and 515 μg/mL against Escherichia coli and Staphylococcus aureus, and substituted hydrazinoquinolones 7-10 showed poor antibacterial activity against gram-positive and gram-negative bacteria compared with other quinolones. Conclusion: Compounds obtained by modifications on C-7 of norfloxacin with the acetylated piperazinyl, halogen atoms, and substituted hydrazinyl showed good in vitro activity - some even better than the original compound.


2008 ◽  
Vol 73 (12) ◽  
pp. 1153-1160 ◽  
Author(s):  
S.O. Podunavac-Kuzmanovic ◽  
V.M. Leovac ◽  
D.D. Cvetkovic

The antibacterial activities of cobalt(II) complexes with two series of benzimidazoles were evaluated in vitro against three Gram-positive bacterial strains (Bacillus cereus, Staphylococcus aureus, and Sarcina lutea) and one Gram-negative isolate (Pseudomonas aeruginosa). The minimum inhibitory concentration was determined for all the complexes. The majority of the investtigated complexes displayed in vitro inhibitory activity against very persistent bacteria. They were found to be more active against Gram-positive than Gram-negative bacteria. It may be concluded that the antibacterial activity of the compounds is related to the cell wall structure of the tested bacteria. Comparing the inhibitory activities of the tested complexes, it was found that the 1-substituted- -2-aminobenzimidazole derivatives were more active than complexes of 1-substituted- 2-amino-5,6-dimethylbenzimidazoles. The effect of chemical structure on the antibacterial activity is discussed.


Author(s):  
Sangeetha R ◽  
Padmini R

  Objective: Protease inhibitors (PIs) are effective antimicrobial agents, and this study was aimed to study the antibacterial efficacy of a PI isolated from the rhizome of Curcuma amada.Methods: A proteinaceous protease inhibitor was isolated from the rhizome of C. amada and purified by Sephadex G-50 gel permeation chromatography. The purified inhibitor was denoted as Curcuma amada protease inhibitor (CAPI). The antibacterial effect of CAPI against Gram-positive and Gram-negative bacteria, the minimal inhibitory concentration (MIC), and minimal bactericidal concentration (MBC) of CAPI was studied in vitro, and the membrane disruption activity of CAPI was also analyzed.Results: CAPI was effective against both Gram-positive and Gram-negative bacteria, with slightly higher concentrations required for Gram-negative bacteria. The MIC ranged from 75 to 100 μg/ml and the MBC ranged from 100 to 125 μg/ml of CAPI. The study of membrane disruption by CAPI revealed the release of cell contents, namely, reducing sugars and proteins from the bacterial cell.Conclusion: A PI was effectively isolated from the rhizome of C. amada, and the isolated inhibitor proved to be a promising antibacterial agent.


2012 ◽  
Vol 9 (4) ◽  
pp. 2493-2500
Author(s):  
Sayali D. Kudale ◽  
Meenakshi N. Deodhar

A series of the Schiff’s bases incorporating coumarin and chalcone moeities, 3-(4-(4-(substituted phenyl)prop-1-ene-3-one) phenylimino) methyl)-4-chloro-2h-chromen-2-one 4(a-g) were synthesized as potential antimicrobial agents. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 4b was found to be most active with an MIC of 20 µg/mL against all the tested organisms.


2015 ◽  
Vol 69 (8) ◽  
Author(s):  
Martin Krátký ◽  
Jana Mandíková ◽  
František Trejtnar ◽  
Vladimír Buchta ◽  
Jiřina Stolaříková ◽  
...  

AbstractProgression of drug resistance among bacterial and fungal pathogens justifies the development of novel antimicrobial agents. Thus, a series of novel sulphamethoxazole-based ureas and imidazolidine- 2,4,5-triones have been designed and synthesised. The urea derivatives were obtained by the reaction of sulphamethoxazole and isocyanates, and their cyclisation to imidazolidine-2,4,5-triones was performed via oxalyl chloride. All synthesised derivatives were evaluated in vitro to determine their activity against gram-positive and gram-negative bacteria, fungi, Mycobacterium tuberculosis, and atypical mycobacteria and their cytotoxicity. The growth of mycobacteria was inhibited within the range of 4-1000 μM and M. tuberculosis was the least-susceptible strain. 4-(3-Heptylureido)- N-(5-methylisoxazol-3-yl)benzenesulphonamide was identified as the most promising compound because it exhibited the highest activity against atypical mycobacteria at minimum inhibitory concentrations, from 4 μM, and with acceptable toxicity (selectivity indices for M. avium and M. kansasii higher than 16 and 62.5, respectively). Gram-positive bacteria, including methicillinresistant Staphylococcus aureus, were inhibited at concentrations starting from 125 μM, whereas the investigated derivatives exhibited almost no antifungal potency and activity against gram-negative species.


Author(s):  
Pratik K. Talpara ◽  
Guarang G. Dubal ◽  
Viresh H. Shah

The synthesis of novel Pyrano[2,3-d]pyrimidine derivatives, had been synthesized by three component domino Knoevenagel hetero Diels-Alder reaction. The products were assayed for their in vitro biological assay antibacterial activity against with two Gram-positive bacteria Staphylococcus aureus MTCC-96, Streptococcus pyogenes MTCC 443, two Gram-negative bacteria Escherichia coli MTCC 442, Pseudomonas aeruginosa MTCC 441 and three fungal strains Candida albicans MTCC 227, Aspergillus Niger MTCC 282, Aspergillus clavatus MTCC 1323 taking ampicillin, chloramphenicol, ciprofloxacin, norfloxacin, nystatin, and griseofulvin as standard drugs. Among the various synthesized heterocyclic compounds, 1b, 1c and 1g are display broad spectrum antibacterial and antifungal activities against both gram-positive and gram-negative bacteria as compared with standard drugs.


Sign in / Sign up

Export Citation Format

Share Document