scholarly journals Synthesis and antibacterial activity of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a] azepin-1-ium bromides and aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines

Author(s):  
Nataliya Demchenko ◽  
Zinaida Suvorova ◽  
Yuliia Fedchenkova ◽  
Tamara Shpychak ◽  
Oleh Shpychak ◽  
...  

The aim of this work is to develop methods of synthesis of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides and aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines and to study their antimicrobial activity against strains of gram-positive and gram-negative bacteria as well as yeast fungi. Materials and methods. 1Н NMR spectra were recorded on Bruker 400 spectrometer operating at frequency of 400 MHz. Antimicrobial activity of the compounds synthesized was evaluated by their minimum inhibitory concentration (MIC) values. Results and discussion. The interaction of 3-arylaminomethyl-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepines with substituted phenacyl bromides produced novel 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides. The latter when refluxed in 10 % solution of NaOH gave aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines. The study of antimicrobial activity of the compounds obtained allowed to find derivatives which are active against С. albicans and S. aureus strains. Among the compounds tested 3-[(41-bromophenylamino)-methyl]-1-[2-(4-methoxyphenyl)-2-oxoethyl]-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromide 5cd appeared to be more active than the reference drug Cefixime and displayed close antimicrobial activity as the antibiotic Linezolid. Conclusions. It was found out that derivatives of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides display broad spectrum of antimicrobial activity and are able to inhibit growth of both bacteria and fungi. S. aureus and C. albicans turned out to be the most sensitive strains to the compounds tested, MIC was in the range of 6.2-25.0 mg/mL. Gram-negative strains of microorganisms were less sensitive to the compounds evaluated and 5fа was the most active derivative displaying antimicrobial activity at the concentration of 50.0 mg/mL. Antimicrobial activity of triazoloazepinium bromide derivatives was similar to that one of Linezolid and Fluconazole reference drugs and more pronounced than the activity of Cefixime. Hence, the data gathered evidence the feasibility of further study of the antimicrobial properties of the most active compounds in in vivo experiments aiming at assessment of the prospects for the creation of new effective and safe antimicrobial drugs based on them

2009 ◽  
Vol 6 (4) ◽  
pp. 1200-1204 ◽  
Author(s):  
P. B. Mallikharjuna ◽  
Y. N. Seetharam

Alkaloid fractions isolated fromStrychnos potatorumL.f. (Loganiaceae) seed were tested for their antimicrobial properties against some pathogenic gram positive, gram negative and acid-fast bacteria and fungi. These fractions have shown considerable antimicrobial activity against both bacteria and fungi at the tested concentrations (100 & 200 μg/mL). Further, the growth ofProteus vulgaris, taphylococcus aureus, Salmonella typhimurium, Vibrio cholerae, Mycobacterium tuberculosis, Aspergillus nigerandCandida albicanswere significantly inhibited. These findings have confirmed the use of this plant in treating of several microbial infections both in traditional and folk medicine in India.


2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


2021 ◽  
Vol 22 (13) ◽  
pp. 7130
Author(s):  
Jeffersson Krishan Trigo-Gutierrez ◽  
Yuliana Vega-Chacón ◽  
Amanda Brandão Soares ◽  
Ewerton Garcia de Oliveira Mima

Curcumin (CUR) is a natural substance extracted from turmeric that has antimicrobial properties. Due to its ability to absorb light in the blue spectrum, CUR is also used as a photosensitizer (PS) in antimicrobial Photodynamic Therapy (aPDT). However, CUR is hydrophobic, unstable in solutions, and has low bioavailability, which hinders its clinical use. To circumvent these drawbacks, drug delivery systems (DDSs) have been used. In this review, we summarize the DDSs used to carry CUR and their antimicrobial effect against viruses, bacteria, and fungi, including drug-resistant strains and emergent pathogens such as SARS-CoV-2. The reviewed DDSs include colloidal (micelles, liposomes, nanoemulsions, cyclodextrins, chitosan, and other polymeric nanoparticles), metallic, and mesoporous particles, as well as graphene, quantum dots, and hybrid nanosystems such as films and hydrogels. Free (non-encapsulated) CUR and CUR loaded in DDSs have a broad-spectrum antimicrobial action when used alone or as a PS in aPDT. They also show low cytotoxicity, in vivo biocompatibility, and improved wound healing. Although there are several in vitro and some in vivo investigations describing the nanotechnological aspects and the potential antimicrobial application of CUR-loaded DDSs, clinical trials are not reported and further studies should translate this evidence to the clinical scenarios of infections.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2793 ◽  
Author(s):  
Ameen Abu-Hashem

Substituted-6-methyl-1-thioxo-1,2-dihydro-3H-furo[3,2-g]pyrimido[1,6-a]quinazolin-3-ones (5a,b) were synthesized from condensation of visnagenone (2a) or khellinone (2b) with 6-amino-thiouracil (3) in dimethylformamide or refluxing of (4a) or (4b) in dimethylformamide. Hence, compounds (5a,b) were used as the starting materials for preparing many new heterocyclic compounds such as; furo[3,2-g]pyrimido[1,6-a]quinazoline (6a,b), furo[3,2-g]thiazolo[2′,3′:2,3]pyrimido[1,6-a]quinazolinone (7a,b), substituted-benzylidene-furo[3,2-g]thiazolo[2′,3′:2,3]pyrimido[1,6-a]quinazoline-3,5-dione (8a–f), 3-oxo-furo[3,2-g]pyrimido[1,6-a]quinazoline-pentane-2,4-dione (9a,b), 1-(pyrazole)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (10a,b), 2-(oxo or thioxo)-pyrimidine-furo[3,2-g]pyrimido[1,6-a]quinazolinone (11a–d), 1-(methylthio)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (12a,b), 1-(methyl-sulfonyl)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (13a,b) and 6-methyl-1-((piperazine) or morpholino)-3H-furo[3,2-g]pyrimido[1,6-a]quinazolin-3-one (14a–d). The structures of the prepared compounds were elucidated on the basis of spectral data (IR, 1H-NMR, 13C-NMR, MS) and elemental analysis. Antimicrobial activity was evaluated for the synthesized compounds against Gram-positive, Gram-negative bacteria and fungi. The new compounds, furothiazolo pyrimido quinazolines 8a–f and 11a–d displayed results excellent for growth inhibition of bacteria and fungi.


2021 ◽  
Vol 10 (2) ◽  
pp. 14-23
Author(s):  
Sanja Kokanov ◽  
Milan Nikolić ◽  
Irena Novaković ◽  
Tamara Todorović ◽  
Nenad Filipović

(Thiazolyl-2-yl)hydrazones (THs) are a group of organic compounds containing both hydrazone and 1,3-thiazole pharmacophores present in many approved drugs. They have been investigated greatly in recent years due to potent anticancer, antibacterial, antifungal, antituberculosis, anti-inflammatory, and antiparasitic activities. In this study, one pyridine-based and two quinoline-based, novel THs were synthesized and characterized by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). The antimicrobial activity of the compounds was tested against five Gram-positive and five Gram-negative bacteria, as well as against three fungi. The antioxidant capacity of the compounds was tested in six antioxidative assays. The results showed that quinoline-based THs were more active against tested Gram-negative bacteria and fungi strains than pyridine-based compounds. All the compounds showed excellent antioxidative activity comparable to or greater than the used standards (vitamin C and Trolox). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters were calculated in-silico. Results pointed to promising good pharmacokinetics profiles of investigated compounds, especially 2-quinoline carboxaldehyde-based compound, which can be a lead drug candidate.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Mark Austin Hanson ◽  
Anna Dostálová ◽  
Camilla Ceroni ◽  
Mickael Poidevin ◽  
Shu Kondo ◽  
...  

Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading microorganisms. These short, cationic peptides have been implicated in many biological processes, primarily involving innate immunity. In vitro studies have shown AMPs kill bacteria and fungi at physiological concentrations, but little validation has been done in vivo. We utilized CRISPR gene editing to delete most known immune-inducible AMPs of Drosophila, namely: 4 Attacins, 2 Diptericins, Drosocin, Drosomycin, Metchnikowin and Defensin. Using individual and multiple knockouts, including flies lacking these ten AMP genes, we characterize the in vivo function of individual and groups of AMPs against diverse bacterial and fungal pathogens. We found that Drosophila AMPs act primarily against Gram-negative bacteria and fungi, contributing either additively or synergistically. We also describe remarkable specificity wherein certain AMPs contribute the bulk of microbicidal activity against specific pathogens, providing functional demonstrations of highly specific AMP-pathogen interactions in an in vivo setting.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Sonja Ž. Đurić ◽  
Sandra Vojnovic ◽  
Tina P. Andrejević ◽  
Nevena Lj Stevanović ◽  
Nada D. Savić ◽  
...  

1,2-Bis(4-pyridyl)ethane (bpa) and 1,2-bis(4-pyridyl)ethene (bpe) were used for the synthesis of polynuclear silver(I) complexes, {[Ag(bpa)]NO3}n (1), {[Ag(bpa)2]CF3SO3.H2O}n (2) and {[Ag(bpe)]CF3SO3}n (3). In complexes 1–3, the corresponding nitrogen-containing heterocycle acts as a bridging ligand between two Ag(I) ions. In vitro antimicrobial activity of these complexes, along with the ligands used for their synthesis, was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and fungi. The silver(I) complexes 1–3 showed selectivity towards Candida spp. and Gram-negative Escherichia coli in comparison to the other investigated bacterial strains, effectively inhibiting the growth of four different Candida species with minimal inhibitory concentrations (MICs) between 2.5 and 25 μg/mL and the growth of E. coli, with MIC value being 12.5 μg/mL. Importantly, complex 2 significantly reduced C. albicans filamentation, an essential process for its pathogenesis. Antiproliferative effect on the normal human lung fibroblast cell line MRC-5 was also evaluated with the aim of determining the therapeutic potential of the complexes 1–3. The interactions of these complexes with calf thymus DNA (ctDNA) and bovine serum albumin (BSA) were studied to evaluate their binding activities towards these biomolecules for possible insights on their mode of action.


The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 490-496 ◽  
Author(s):  
BrettR. Moyer ◽  
Alex N. Rock ◽  
Dale H. Clayton

Abstract Most species of birds have a uropygial gland, also known as a preen gland, which produces oil that birds spread through their plumage when preening. The plumage of waterfowl deprived of uropygial oil becomes brittle and is subject to breakage. For other groups of birds, however, the importance of preen oil remains unclear. Previous workers have argued that preen oil may serve little or no function in Columbiforms (pigeons and doves). We tested that assertion by removing uropygial glands from Rock Doves (Columba livia) and assessing their plumage condition after several months. The results of that experiment showed significant degradation of plumage in the absence of oil. Our results are the first rigorous demonstration that preen oil is important for plumage condition in nonwaterfowl. We tested one possible function of preen oil—that it has insecticidal properties and that reduction in plumage condition on birds without glands is due to an increase in ectoparasites. We tested that hypothesis for feather-feeding lice (Phthiraptera:Ischnocera) using both in vitro and in vivo experiments. Lice raised in an incubator died more rapidly on feathers with preen oil than on feathers without oil, which suggests that preen oil may help combat lice. However, removal of the preen gland from captive birds had no significant effect on louse loads over the course of a four-month experiment. Although the results of our in vivo experiments suggest that preen oil may not be an important defense against lice, further experiments are needed. We also consider the possibility that preen oil may protect birds against other plumage-degrading organisms, such as bacteria and fungi.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Anwar Ali Chandio ◽  
Ayaz Ali Memon ◽  
Shahabuddin Memon ◽  
Fakhar N. Memon ◽  
Qadeer Khan Panhwar ◽  
...  

Present study deals with the synthesis of the p-tert-butylcalix[4]arene diamide derivative as ligand (L) and its Fe3+ complex, followed by its characterization using TLC and FT-IR, while UV-Vis and Job’s plot study were performed for complex formation. Antimicrobial activity of the derivative (L) and its metal complex was carried out by the disc diffusion method against bacteria (Escherichia coli and Staphylococcus albus) and fungi (R. stolonifer). Different concentrations of the derivative (L) (6, 3, 1.5, 0.75, and 0.37 μg/mL) and its Fe3+ complex were prepared, and Mueller–Hinton agar was used as the medium for the growth of microorganisms. Six successive dilutions of the derivative (L) and Fe3+ complex were used against microorganisms. Two successive dilutions (6 and 3 μg/mL) of the derivative (L) showed antibacterial action against both Gram-positive and Gram-negative bacteria. In addition, three successive dilutions (6, 3, and 1.5 μg/mL) of the derivative (L) showed antifungal activity. However, all of six dilutions of the Fe3+ complex showed antimicrobial activity. Derivative (L) showed 3 and 1.5 μg/mL minimum inhibitory concentrations (MIC) against bacteria and fungi, respectively. On the contrary, its Fe3+ complex showed 0.37 μg/mL value of MIC against bacteria and fungi. Hence, Fe3+ complex of the derivative (L) was found to be a more effective antimicrobial agent against selected bacteria and fungi than the diamide derivative (L).


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.


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