scholarly journals Synthesis, Characterization, and Antibacterial Activities of 1H-Imidazo [5, 6-f] [1,10] Phenanthroline-2(3H)-Thione and Its Ni(II) and Cu(II) Complexes

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Radiet Anbessie Tirkeso ◽  
Tilahun Wubalem Tsega ◽  
Gebru G/Tsadik Amdemichael

As multidrug resistant pathogens are emerging, the search for novel potent drug candidates is ever going. Heterocycles are known by their broad spectrum of biological activities, so a search for a new drug from heterocycles can elevate the chance of success. The aim of this study was to obtain novel potent antimicrobial compounds. In line with this, 1H-imidazo [5, 6-f] [1,10] phenanthroline-2(3H)-thione and its complexes (Ni(II) and Cu(II)) were synthesized, characterized, and evaluated against bacterial strains. The compounds were characterized by elemental analyses (C, H, N, and S), FT-IR, 1H-NMR, 13C-NMR, AAS, UV-Vis spectra, and molar conductivity measurement. The results showed that the ligand is bidentate, and the molar conductivity measurement indicates that complexes are electrolytic. Electronic spectral study showed octahedral and distorted octahedral geometry for the Ni(II) and Cu(II) complex, respectively. The ligand and its complexes were screened against four bacterial strains using disk diffusion method. The result revealed that the Ni(II) complex showed more bioactivity than gentamicin against Staphylococcus aureus and Escherichia coli, while the Cu(II) complex is more active than the Ni(II) complex against Bacillus subtilis. Both Cu(II) and Ni(II) complexes exhibit higher antibacterial activities than the free ligand.

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Giovanna Pesavento ◽  
Valentina Maggini ◽  
Isabel Maida ◽  
Antonella Lo Nostro ◽  
Carmela Calonico ◽  
...  

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.


Author(s):  
Maysa Serpa ◽  
Juliana Amália Fonte Bôa do Nascimento ◽  
Mirian Fátima Alves ◽  
Maria Isabel Maldonado Coelho Guedes ◽  
Adrienny Trindade Reis ◽  
...  

Antimicrobial resistance is a current and important issue to public health, and it is usually associated with the indiscriminate use of antimicrobials in animal production. This study aimed to evaluate the antimicrobial susceptibility profile in bacterial isolates from pigs with clinical respiratory signs in Brazil. One hundred sixty bacterial strains isolated from pigs from 51 pig farms in Brazil were studied. In vitro disk-diffusion method was employed using 14 antimicrobial agents: amoxicillin, penicillin, ceftiofur, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, oxytetracycline, tetracycline, erythromycin, tilmicosin, florfenicol, lincomycin, and sulfadiazine/trimethoprim. The majority of isolates were resistant to at least one antimicrobial agent (98.75%; 158/160), while 31.25% (50/160) of the strains were multidrug resistant. Streptococcus suis and Bordetella bronchiseptica were the pathogens that showed higher resistance levels. Haemophilus parasuis showed high resistance levels to sulfadiazine/trimethoprim (9/18=50%). We observed that isolates from the midwestern and southern regions exhibited four times greater chance of being multidrug resistant than the isolates from the southeastern region studied. Overall, the results of the present study showed a great level of resistance to lincomycin, erythromycin, sulfadiazine/trimethoprim, and tetracycline among bacterial respiratory pathogens isolated from pigs in Brazil. The high levels of antimicrobial resistance in swine respiratory bacterial pathogens highlight the need for the proper use of antimicrobials in Brazilian pig farms.


2022 ◽  
Vol 82 ◽  
Author(s):  
Q. A. Naseer ◽  
X. Xue ◽  
X. Wang ◽  
S. Dang ◽  
S. U. Din ◽  
...  

Abstract Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in “De Man, Rogasa, and Sharp” broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell- free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.


2020 ◽  
Vol 17 (6) ◽  
pp. 745-756
Author(s):  
Adnan Cetin ◽  
Havva Kurt

Background: The pyrazole structure is an important heterocyclic structure and plays critical roles in agriculture, industrial and medicine. Furthermore, compounds containing pyrazole are known to exhibit various biological properties such as antibacterial, antifungal, anticancer, antiinflammatory, antidepressant, antipyretic, antiviral, anti-tubercular and anti-HIV activities. Because of these properties, pyrazole molecules have become a very popular topic for organic chemists. Methods: A series newly substituted pyrazole molecules were synthesized and characterized. Their antimicrobial activities were investigated by disk diffusion method against some gram positive bacteria and gram negative bacteria. Results: The present results indicated that the some test compounds were active in a broad spectrum against important human pathogenic microorganisms. The substituted pyrazoles including carbazone (7a, b) and thiazolidine (8a, b) showed a wide variety of biological activities. The results showed that synthesized pyrazole, compounds 7b and 8b are highly active and more potent in both biological and molecular docking simulation studies. Conclusion: The synthesized pyrazole molecules showed moderate antibacterial activities against the tested microorganism compared to antibiotic drug. Some test compounds (7b and 8b) might be used as new antibacterial agents.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1470 ◽  
Author(s):  
Cristiana Radulescu ◽  
Lavinia Claudia Buruleanu ◽  
Cristina Mihaela Nicolescu ◽  
Radu Lucian Olteanu ◽  
Marius Bumbac ◽  
...  

The therapeutic benefits of extracts obtained from different red grape fractions were thoroughly studied, however, data regarding the comparison of phytochemical extracts prepared from the same varieties coming from organic versus conventional management systems are rather lacking. The present study aimed at comparing some of the phytochemical characteristics and antimicrobial activity of hydroalcoholic (50% v/v) extracts obtained from four varieties of red grapes cultivated respectively in organic and conventional vineyards. Total flavonoid content, total phenolic compounds, and antioxidant activity were determined by molecular absorption spectroscopy. Antimicrobial activity of the studied extracts was evaluated against common bacterial strains isolated from different habitats according to specific lab procedures. The analyses were performed in solid broths by applying the disk diffusion method, which allowed for the simultaneous determination of the spectrum of the sensitivity of the tested bacteria as well as the values of the minimum inhibition concentration (MIC). It was found that favorable antagonistic activities against the tested bacteria strains were exhibited by the hydroalcoholic extracts from the seeds of the organic varieties, respectively the skin of the conventional varieties.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kavita Devi ◽  
Yumna Asmat ◽  
Sonika Jain ◽  
Swapnil Sharma ◽  
Jaya Dwivedi

Oxazolidinone, either mononuclear or condensed with other heterocyclics, has established its importance in medicinal chemistry. A variety of biological activities have been reported by oxazolidinone derivatives. The present work describes the synthesis of several oxazolidinone derivatives, 3-(2-(7-chloroquinoline-4-ylamino)ethyl)-2-imino-5-(4-chloro/nitro/methoxy benzylidene)oxazolidin-4-one 4(a–c) and 4-(2-(7-chloroquinolin-4-ylamino)ethyl)-2(4-chloro/nitro/methoxy-benzylidene)-1,6-diox-4,9-di-azaspiro[4,4]nonane-3,8-dione 5(a–c). Synthesized compounds (1, 3, 4a, 5a, and 5c) were screened against bacterial strains such asS. aureus(MTCC 96) andE. coli(MTCC119) and fungal strainsA. niger(MTCC 1344) andC. albicans(MTCC 871) compared with penicillin for bacteria and fluconazole for fungi as reference drugs by disk diffusion method. All synthesized compounds were identified by the means of IR, NMR, and MS.


2020 ◽  
Vol 7 (3) ◽  
pp. 463-468
Author(s):  
Hong Thien Van ◽  
Dang Gia Man Nguyen ◽  
Nguyen Tuong An Quynh ◽  
Van Son Le

In this study, the antibacterial activity of ethanolic extract from the leaves of four Rutaceae species, including Acronychia pedunculata, Clausena excavata, Glycosmis pentaphylla and Luvunga scandens, were performed using the agar disk diffusion method for the first time. The ethanolic extracts from the leaves of A. pedunculata and G. pentaphylla were able to resist against all six bacterial strains with zones of inhibition for Bacillus cereus (17.3±2.1 mm, 20.8±1.0 mm) Staphylococcus aureus (8.5±0.5 mm, 17.6±0.3 mm) Escherichia coli (16.7±2.1 mm, 15.3±1.2 mm), Pseudomonas aeruginosa (11.7±0.6 mm, 14.0±1.7 mm), Salmonella enteritidis (22.3±0.6 mm, 24.6±0.5 mm) and Salmonella typhimurium (9.5±0.9 mm, 8.3±0.6 mm). On the other hand, the ethanolic extract of C. excavata leaf was resistant to B. cereus (12.3±0.6 mm), S. aureus (11.6±0.5 mm), E. coli (11.5±2.1 mm), P. aeruginosa (10.6±0.3 mm) while B. cereus (8.2±0.3 mm), S. aureus (9.3±0.6 mm), E. coli (8.5±0.5 mm) and S. typhimurium (8.3±0.6 mm) were inhibited by the ethanolic extract of L. scandens leaf. This study could provide necessary information for further application of these species in medicine.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ionuţ Ledeţi ◽  
Vasile Bercean ◽  
Anda Alexa ◽  
Codruţa Şoica ◽  
Lenuţa-Maria Şuta ◽  
...  

Background. Both 1,2,3- and 1,2,4-triazoles are nowadays incorporated in numerous antibacterial pharmaceutical formulations.Aim. Our study aimed to prepare three substituted 1,2,4-triazoles and to evaluate their antibacterial properties.Materials and Methods. One disubstituted and two trisubstituted 1,2,4-triazoles were prepared and characterised by physical and spectroscopic properties (melting point, FTIR, NMR, and GC-MS). The antibacterial properties were studied against three bacterial strains:Staphylococcus aureus(ATCC 25923),Escherichia coli(ATCC 25922), andPseudomonas aeruginosa(ATCC 27853), by the agar disk diffusion method and the dilution method with MIC (minimal inhibitory concentration) determination.Results. The spectroscopic characterization of compounds and the working protocol for the synthesis of the triazolic derivatives are described. The compounds were obtained with 15–43% yields and with high purities, confirmed by the NMR analysis. The evaluation of biological activities showed that the compounds act as antibacterial agents againstStaphylococcus aureus(ATCC 25923), while being inactive againstEscherichia coli(ATCC 25922) andPseudomonas aeruginosa(ATCC 27853).Conclusions. Our results indicate that compounds containing 1,2,4-triazolic moiety have great potential in developing a wide variety of new antibacterial formulations.


Author(s):  
Ganesamoorthy Thirunarayanan ◽  
R. Senbagam ◽  
M. Rajarajan ◽  
V. Manikandan ◽  
S. Balaji ◽  
...  

A series of ten substituted (E)-2-benzylidene-N-methylhydrazinecarbothioamides were synthesized from 4-methyl-3-thiosemicarbazide with substituted benzaldehydes. All the synthesized compounds were in good agreement with elemental and spectral data (UV, FT-IR, 1H NMR and 13C NMR). The assigned UV λmax (nm), IR νC=N (cm-1), NMR δ1H (ppm) CH=N and δ13C (ppm) C=N spectral data of (E)-2-benzylidene-N-methylhydrazinecarbothioamides correlated with Hammett constants using single and multi-regression analysis. From the results of correlation analysis substituent effects on the spectral data have been discussed. The antibacterial activity of (E)-2-benzylidene-N-methylhydrazinecarbothioamides have been studied with three Gram-positive pathogenic bacterial strains namely (B. subtilis, S. aureus and S. pyogens) and two Gram-negative strains (E. coli and P. aeruginosa). The antifungal activity of (E)-2-benzylidene-N-methyl hydrazones studied with three fungal species (A. flavus, A. niger, T. viride) using disk diffusion method. 


Author(s):  
BALAJI SUNDARAMAHALINGAM ◽  
CHANDAN SANTHILAL ◽  
NARAYANAN MARIMUTHU

Objectives: The present investigation aimed to identify the multidrug resistance Escherichia coli bacteria in drinkers of poultry stations located across the Virudhunagar district, Tamil Nadu, India. Because water is the most important part of digestion in the growing chicks of poultry stations, but the quality of water supplied is often negotiated and the water drinkers in poultry farms has becoming the heavenly ground for antibiotic resistance (ABR) generation. Methods: Hence in the present investigation water samples from the drinkers of five poultry stations were collected and analyzed for E. coli resistance bacteria using the disk diffusion method of Bauer–Kirby technique. Results: Screening for ABR against the disc of penicillin, ampicillin, chloramphenicol, streptomycin, kanamycin, and cephalosporin were performed. Among the water samples collected from drinkers of five sampling sites, three sampling sites were found to show resistance bacteria against the different antibacterial disc used. Conclusion: To overcome the development of ABR bacterial strains from poultry stations point of use disinfectant techniques rather than using chlorine and other chemical disinfectants can be developed to alleviate this problem.


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