Imidazole Derivatives and their Antibacterial Activity – a Mini-Review

2020 ◽  
Vol 20 ◽  
Author(s):  
Andrei Șerban Gâz ◽  
Francisc Andrei Boda ◽  
Rahela Roxana Pop
Keyword(s):  
Antibacterial Activity ◽  
Relevant Literature ◽  
New Drugs ◽  
Public Health Issue ◽  
Bacterial Strains ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Gram Positive ◽  
Gram Negative ◽  
Imidazole Derivatives ◽  
Chemical Structures

Background:: The development of drug resistance by bacterial strains is a public health issue, being the main cause for the decrease in effectiveness of numerous antibiotics. In this context, it is essential to find new drugs with better antibacterial activity. Objective:: The authors proposed to cover relevant literature, published following the review article written by Rani et al., illustrating chemical structures and antibacterial activity of some imidazole derivatives. Method:: Approximately 100 scientific articles, presenting more than 150 compounds have been reviewed. The most relevant data have been extracted and systematically arranged in figures and tables. Results:: The reviewed studies used a broad number of bacterial strains, however Staphylococcus aureus as Gram-positive, and Escherichia coli as Gram-negative bacterial strains were most frequently used to assess the activity of these compounds. Conclusion:: Some of the compounds showed promising results against both Gram-positive and Gram-negative bacterial strains, thus further analysis should be performed in terms of toxicity, pharmacokinetics and pharmacodynamics. Additional screening of these imidazole derivatives could lead to useful compounds with potential broad-spectrum antibacterial activity against resistant pathogens.

scholarly journals Antibacterial Potential of Aloe weloensis (Aloeacea) Leaf Latex against Gram-Positive and Gram-Negative Bacteria Strains

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Yohannes Kelifa Emiru ◽  
Ebrahim Abdela Siraj ◽  
Tekleab Teka Teklehaimanot ◽  
Gedefaw Getnet Amare
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Inhibition Zone ◽  
Antibacterial Activities ◽  
Maximum Activity ◽  
New Drugs ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative

Objective. To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. Methods. The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). Results. The tested concentrations of the latex ranging between 400 and 600 mg·mL−1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. Conclusion. The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.

scholarly journals The spectrum of antibacterial activity of human defensins and cathelicidin against gram-positive and gram-negative bacterial strains isolated from hospitalized patients

2020 ◽  
Author(s):  
Albert Bolatchiev
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Hospitalized Patients ◽  
New Drugs ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Conventional Antibiotics ◽  
Human Defensins

AbstractBackgroundTo date, there is a spread of resistance of microorganisms to antibiotics. To solve this problem, the search and development of new drugs with antibacterial activity is necessary. Antimicrobial peptides (AMPs) have pronounced antibacterial activity and may be promising candidates for the role of new drugs. Besides, AMPs can be used to overcome conventional antibiotics resistance due to the possible synergistic effect. In this work, the combined effect of some AMPs (human defensins, HNP-1, hBD-1, hBD-3 and cathelicidin, LL-37) with conventional antibiotics (vancomycin and imipenem) against gram-positive (Enterococcus faecalis; Staphylococcus aureus, methicillin-sensitive, MSSA, and methicillin-resistant, MRSA) and gram-negative (Escherichia coli; Klebsiella pneumoniae; Pseudomonas aeruginosa) bacterial strains was investigated.MethodsBacterial strains were isolated from hospitalized patients of the intensive care unit. Commercially available AMPs (HNP-1, hBD-1, hBD-3, LL-37 by Cloud-Clone Corp., USA) and antibiotics, vancomycin (Sandoz, Slovenia) and imipenem (Merck Sharp and Dohme, USA) were used. Antibiotic resistance phenotypes of isolated bacterial strains were carried out using the disk diffusion method. The standard checkerboard assays were used to study minimum inhibitory concentrations (MIC) of antimicrobials. The combined microbicidal effect of two substances (AMP+conventional antibiotic) was assessed by the fractional inhibitory concentration index (FICI). If FICI ≤ 0,5, then it was considered that two substances showed synergism of action; if 0.5 < FICI < 4 – no interaction; if FICI > 4 – antagonism.ResultsAll studied AMPs had antibacterial activity against the studied strains. hBD-3 showed the lowest MICs compared to other AMPs. MIC of hBD-3 against S. aureus (MSSA and MRSA), E. coli, K. pneumoniae was the same – 0.5 mg/L, and against P. aeruginosa it was 2 mg/L. The combinations HNP-1+vancomycin (against E. faecalis) and hBD-3+imipenem (against E. coli, K. pneumoniae, P. aeruginosa) according to FICI values have shown the synergistic effect. The results of this study can be used to develop novel antibiotics based on AMPs. Also, in some cases, AMPs can help to overcome resistance to conventional antibiotics.

scholarly journals Multitargeting Antibacterial Activity of a Synthesized Mn2+ Complex of Curcumin on Gram-Positive and Gram-Negative Bacterial Strains

ACS Omega ◽  
2020 ◽  
Vol 5 (27) ◽  
pp. 16342-16357
Author(s):  
Tanmoy Saha ◽  
Prince Kumar ◽  
Nayim Sepay ◽  
Durba Ganguly ◽  
Kanchan Tiwari ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative

scholarly journals Evaluation of antibacterial activity of vitamin C against human bacterial pathogens

2023 ◽  
Vol 83 ◽  
Author(s):  
S. Mumtaz ◽  
S. Mumtaz ◽  
S. Ali ◽  
H. M. Tahir ◽  
S. A. R. Kazmi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Vitamin C ◽  
Bacterial Infections ◽  
Unmet Need ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Adjunct Treatment

Abstract Now a day’s multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.

scholarly journals Antibacterial activity of Beta vulgaris L. pomace extract

2011 ◽  
pp. 263-269 ◽  
Author(s):  
Aleksandra Velicanski ◽  
Dragoljub Cvetkovic ◽  
Sinisa Markov ◽  
Jelena Vulic ◽  
Sonja Djilas
Keyword(s):  
Antibacterial Activity ◽  
Beta Vulgaris ◽  
Staphylococcus Epidermidis ◽  
Control Sample ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Natural Isolates

Antibacterial activity of Beta vulgaris L. (beetroot) pomace extract (concentration 100 mg/ml) was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates). Disc diffusion method with 15 ?l of extract and agar-well diffusion method with 50 and 100 ?l were used. Antibiotic (cefotaxime/clavulanic acid) was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth) appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 ?l of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared.

In vitro Antibacterial Activity of 7-Substituted-6-Fluoroquinolone and 7-Substituted-6,8-Difluoroquinolone Derivatives

Chemotherapy ◽  
2017 ◽  
Vol 62 (3) ◽  
pp. 194-198 ◽  
Author(s):  
Socorro Leyva-Ramos ◽  
Denisse de Loera ◽  
Jaime Cardoso-Ortiz
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
New Drugs ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Disk Diffusion Method ◽  
Gram Negative

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.

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 Activity of Floral Petals of Some Angiosperms

2019 ◽  
pp. 1-5 ◽  
Author(s):  
L. Rajanna ◽  
N. Santhosh Kumar ◽  
N. S. Suresha ◽  
S. Lavanya
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Bacterial Strains ◽  
Inhibitory Zone ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Assay

The in vitro antibacterial assay was carried out against both Gram positive (B. cerus and S. aureus) and Gram negative (E. coli and K. pneumoniae) bacteria. Floral petals of 20 different species of plants were collected and tested for antibacterial activity. The result showed that the petals were active against both Gram positive and Gram negative. Out of 20 floral petals tested, 19 floral petals exhibited antibacterial activity against selected bacterial strains. The minimal inhibitory zone of floral petal discs against human pathogenic bacteria varies from 2 – 6 mm. Rosa carolina and Ruellia tuberosa showed significance inhibition zone for all the bacterial strains while Lantana camara does not show inhibition zone for any of these pathogenic bacteria.

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