Synthesis and antimicrobial properties of new 2-((4-ethylphenoxy)methyl)benzoylthioureas

2011 ◽  
Vol 65 (1) ◽  
Author(s):  
Carmen Limban ◽  
Alexandru Missir ◽  
Ileana Chirita ◽  
George Nitulescu ◽  
Miron Caproiu ◽  
...  

AbstractNew acylthiourea derivatives, 2-((4-ethylphenoxy)methyl)-N-(phenylcarbamothioyl)benzamides, were tested by qualitative and quantitative methods on various bacterial and fungal strains and proved to be active at low concentrations against Gram-positive and Gram-negative bacteria as well as fungi. These compounds were prepared by the reaction of 2-((4-ethylphenoxy)methyl)benzoyl isothiocyanate with various primary aromatic amines, and were characterised by melting point and solubility. The structures were identified by elemental analysis, 1H and 13C NMR, and IR spectral data. The level of antimicrobial activity of the new 2-((4-ethylphenoxy)methyl)benzoylthiourea derivatives was dependent on the type, number and position of the substituent on the phenyl group attached to thiourea nitrogen. The iodine and nitro substituents favoured the antimicrobial activity against the Gram-negative bacterial strains, while the highest inhibitory effect against Gram-positive and fungal strains was exhibited by compounds with electron-donating substituents such as the methyl and ethyl groups.

2019 ◽  
Vol 70 (6) ◽  
pp. 1996-1999
Author(s):  
Catalin Araniciu ◽  
Smaranda Dafina Oniga ◽  
Cristina Ioana Stoica ◽  
Mariana Carmen Chifiriuc ◽  
Marcela Popa ◽  
...  

Considering the promising antimicrobial activity of compounds bearing the thiazole or the oxadiazole rings in their structures, we set out to obtain new antimicrobial molecules bearing the 2-(thiazol-5-yl)-1,3,4-oxadiazole schaffold. The structures of the 8 new compounds obtained was confirmed by physicochemical characterization including: 1H-NMR, MS and elemental analysis. Antimicrobial activity was investigated against 5 Gram-positive bacterial strains, 2 Gram-negative bacterial strains and 2 fungal strains. The newly synthesized compounds showed modest antimicrobial activity.


Author(s):  
Ankita A. Bhalu ◽  
Pooja Moteriya ◽  
Sumitra Chanda ◽  
Shipra H. Baluja

Some new dihydropyrano[c]chromenes derivatives are synthesized from 4-hydroxycoumarin. The structure of newly synthesized compounds was confirmed by mass, 1H NMR and IR spectroscopy. Further, antimicrobial screening of these synthesized compounds was done against some bacterial (Gram positive as well as Gram negative) and fungal strains in N,N-dimethylformamide. It is observed that some of synthesized compounds exhibited significant antibacterial activity against Gram positive bacterial strains. The selected fungal strains were most resistant for the studied compounds as none of the synthesized compounds showed activity against any of the fungal strain studied. The best antibacterial activity was shown by ABR-10.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Helmoz R. Appelt ◽  
Julieta S. Oliveira ◽  
Roberto C. V. Santos ◽  
Oscar E. D. Rodrigues ◽  
Maura Z. Santos ◽  
...  

A series of D-glucosamine derivatives were synthesized (2–4) and evaluated for their antimicrobial activity. Some of the compounds investigated have shown significant antimicrobial activity against Gram-positive and Gram-negative bacterial strains as well as a few fungal strains. The results suggest that the presence of sugar moiety is necessary to biological activity.


2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hessa H. Al-Rasheed ◽  
Monirah Al Alshaikh ◽  
Jamal M. Khaled ◽  
Naiyf S. Alharbi ◽  
Ayman El-Faham

Novel series of 4,6-disubstituted-1,3,5-triazines containing hydrazone derivatives were synthesized employing ultrasonic irradiation and conventional heating. The ultrasonication gave the target products in higher yields and purity in shorter reaction time compared with the conventional method. IR, NMR (H 1 and C 13), elemental analysis, and LC-MS confirmed the structures of the new products. The antimicrobial and antifungal activities were evaluated for all the prepared compounds against some selected Gram-positive and Gram-negative bacterial strains. The results showed that only two compounds 7i (pyridine derivative) and 7k (4-chlorobenzaldehyde derivative) displayed biological activity against some Gram-positive and Gram-negative bacteria, while the rest of the tested compounds did not display any antifungal activity.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.


2019 ◽  
pp. 27-32
Author(s):  
Emőke Mihok ◽  
Éva György ◽  
Endre Máthé

Wild berry is an excellent source of phytonutrients and/or bioactive compounds associated with significant therapeutic properties, so that they have been utilized in folk medicine and traditional nutrition throughout centuries. Multiple health-promoting effects, such as anti-inflammatory, anti-diabetic, anti-heart and coronary disease properties were attributed to such wild berries. It has also been proved that berries could feature antimicrobial effects that could be of a great importance for the prevention of food-feed poisoning and fighting back antibiotic resistance. In this study, we investigated the antimicrobial properties of lingonberry (Vaccinium vitis-idaea), raspberry (Rubus idaeus) and blackberry (Rubus fruticosus) crude and ethanolic extracts prepared from fruits obtained from the spontaneous flora of Eastern Carpathian Mountains situated in Transylvania. The antimicrobial effect of crude and alcoholic extracts were assessed on four Gram-negative, five Gram-positive bacteria and one yeast species using the agar diffusion method. The studied bacteria can cause food or feed spoilage and foodborne diseases. Our results indicate the significant inhibitory effect of lingonberry extracts in the case of Gram-negative bacteria like Proteus vulgaris and Salmonella Hartford, while among Gram-positive bacteria the strongest inhibitory effect was observed for Bacillus species like B. cereus, B. subtilis, B. mojavensis and Micrococcus luteus. The raspberry and blackberry extracts featured milder inhibitory effects in the case of the studied bacteria species. Furthermore, we have studied the crude or ethanolic extract combinations associated antimicrobial effects synergistic/additive or antagonistic properties. Interestingly, the triple and double ethanolic extract mixes had stronger antimicrobial properties, whereas the crude extract mixes showed relatively reduced effects, if any. Our results indicate that the antimicrobial activity of studied fruit extracts obtained from wild berries can vary upon the applied extraction method and their combination formulae, so that all these considerations must be taken into account when such fruit extracts are considered for foodstuff development.


Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 324 ◽  
Author(s):  
Shayma Thyab Gddoa Al-sahlany ◽  
Ammar Altemimi ◽  
Alaa Al-Manhel ◽  
Alaa Niamah ◽  
Naoufal Lakhssassi ◽  
...  

A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker’s yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25–30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50–90 °C for 30 min, and tolerated a pH range of 5–7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dhiraj Dutta ◽  
Swagata Goswami ◽  
Rama Dubey ◽  
Sanjai K. Dwivedi ◽  
Amrit Puzari

Abstract Background Growing microbial resistance towards the existing antimicrobial materials appears as the greatest challenge for the scientific community and development of new antimicrobial materials has become an important research objective. Results In this work, antimicrobial activity of silver-coated hollow poly(methylmethacrylate) microspheres (PMB) having a diameter of 20–80 µm was evaluated against two bacterial strains, Gram-positive Bacillus subtilis (MTCC 1305) and Gram-negative Escherichia coli (MTCC 443). The polymeric PMMA microspheres were synthesized by solvent evaporation technique and were further coated with silver (Ag) under microwave irradiation on their outer surface using an electroless plating technique. It was observed that Ag was uniformly coated on the surface of microspheres. Characterization of the coated microspheres was performed using optical microscope (OMS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy, FTIR spectroscopy and thermogravimetric analysis (TGA) techniques. We have shown that the silver-coated microspheres were potent bactericidal material for water as they are highly active against the tested microorganisms. The results of the antibacterial tests indicated that APMB particles showed enhanced inhibition rate for both Gram-positive and Gram-negative bacteria and also exhibited dose-dependent antibacterial ability. The diameters of zone of inhibition were14.3 ± 0.2 mm against B. subtilis and 15.2 ± 0.9 mm against E. coli at a concentration of 8 mg. At this concentration, total removal of both Bacillus subtilis and Escherichia coli was observed. The results of shake flask technique for a concentration of 8 mg showed no bacterial presence after 24 h in both the cases. In other words, the material acted efficiently in bringing down the bacterial count to zero level for the tested strains. During the experiments, we have also confirmed that use of this material for water disinfection does not cause leaching of silver ion in to the water solution. The material can be successfully regenerated by backwashing with water. Conclusions Considering the cost-effective synthesis, ability to regenerate and very low level of leaching of the material, it can be projected as an advanced material for water disinfection and antimicrobial application.


Author(s):  
N. A. Bagnyuk ◽  
O. A. Nazarchuk ◽  
Y. M. Babina ◽  
R. M. Chornopyshchuk ◽  
A. V. Kulyk

Recently, among hospital strains of microorganisms, an increase in the number of antiseptic-resistant strains of opportunistic pathogens has been registered, which significantly affects the effectiveness of these drugs. It is important to study their antimicrobial efficacy to justify rational use. The aim is to conduct a comparative study of the antimicrobial efficacy of antiseptics of decamethoxine, chlorhexidine, polyhexanide. During study we examined the antimicrobial activity against 186 clinical strains of microorganisms (Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus spp., Enterobacter spp.) isolated from patients with infectious complications in the postoperative period. The minimum inhibitory (MIC) and bactericidal concentrations (MBC) of 0.02 % and 0.1 % decamethoxine, 0.05 % chlorhexidine bigluconate, 0.1 % polyhexanide were determined; antimicrobial efficacy of drugs was evaluated by the index of antiseptic activity by conventional methods. The study found high antimicrobial properties of decamethoxine, chlorhexidine, which had a high bactericidal effect on clinical strains of S. aureus, Enterococcus spp., Enterobacter spp. Proved the benefits of antimicrobial activity of the drug based on decamethoxine (p<0.001). The polyhexanide has pronounced antimicrobial properties against A. baumannii, bacteria of the family Enterobactericae, P. aeruginosa. Thus, the leading gram-positive (Staphylococcus aureus, enterococci) and gram-negative pathogens (enterobacteria, acinetobacteria, pseudomonads) are sensitive to polyhexanide, chlorhexidine and the domestic drug decamethoxin, with a probable advantage of the antimicrobial properties of the latter over all gram-positive and most gram-negative microorganisms.


Sign in / Sign up

Export Citation Format

Share Document