Antimicrobial Properties of Mono- and Di-fac-rhenium Tricarbonyl 2-Pyridyl-1,2,3-triazole Complexes

2016 ◽  
Vol 69 (5) ◽  
pp. 489 ◽  
Author(s):  
Sreedhar V. Kumar ◽  
Warrick K. C. Lo ◽  
Heather J. L. Brooks ◽  
Lyall R. Hanton ◽  
James D. Crowley

A family of mono- and di-fac-rhenium tricarbonyl 2-pyridyl-1,2,3-triazole complexes with different aliphatic and aromatic substituents was synthesized in good-to-excellent yields (46–99 %). The complexes were characterized by 1H and 13C NMR spectroscopy, infrared spectroscopy, electronic (UV-visible) spectroscopy, high-resolution electrospray mass spectrometry, and elemental analyses. In four examples, the solid-state structures of the rhenium(i) complexes were confirmed by X-ray crystallography. The family of the mono- and di-rhenium(i) complexes and the corresponding 2-pyridyl-1,2,3-triazole was tested for antimicrobial activity in vitro against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Agar-based disk diffusion assays indicated that most of the rhenium(i) complexes were active against Staphylococcus aureus and that the cationic rhenium(i) complexes were more active than the related neutral systems. However, in all cases, the minimum inhibitory concentrations for all the complexes were modest (i.e. 16–1024 µg mL–1).

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1513-1524 ◽  
Author(s):  
Uwe Monkowius ◽  
Manfred Zabel ◽  
Michel Fleck ◽  
Hartmut Yersin

The P∩N-ligands Ph2Pqn, 1, Ph2 Piqn, 2, Ph2 Ppym, 3, and the As∩N-ligands Ph2Asqn, 4, Ph2Asiqn, 5, (Ph = phenyl, qn = 8-quinoline, iqn = 1-isoquinoline, pym = 2-pyrimidine) have been synthesized, the ligands 2 and 5 for the first time. Their ligand properties were probed by the synthesis of gold(I) complexes. Reaction with (tht)AuCl (tht = tetrahydrothiophene) yielded the chlorogold complexes Ph2RP-Au-Cl (R = qn, 6; iqn, 7; pym, 8) and Ph2RAs-Au-Cl (R = qn, 9; iqn, 10) in high yields. Further treatment of 7 and 8 with one equivalent of AgBF4 provided the complexes [(Ph2Piqn)Au]BF4, 11, [(Ph2Ppym)Au]BF4, 12, and [(Ph2Piqn)Au(tht)]BF4, 14. For comparison, the previously reported complex [(Ph2Ppy)Au]BF4 (py = pyridine), 13, was re-investigated. The compounds were characterized by elemental analyses, mass spectrometry and NMR spectroscopy. In addition, the solid-state structures of 2, 3, 6, 7, 9 - 14 have been determined by X-ray crystallography. The chloro-gold compounds crystallize in the common rod-like structure known from R3EAuCl (R = aryl, E = P, As) complexes without further aggregation via aurophilic interactions. In all cases the phosphine acts as a monodentate ligand. In the solid state compounds 11 - 13 feature an unprecedented cyclic trinuclear aggregation pattern, in which the Au(I) atoms are linearly coordinated by the bridging phosphine ligands forming a cyclic (P-Au-N)3 arrangement. The resulting twelvemembered ring is further stabilized by Au · · · Au interactions. Due to the presence of these Au · · · Au contacts, 11 - 13 are emissive in the solid state but not in solution


2007 ◽  
Vol 62 (10) ◽  
pp. 1339-1342 ◽  
Author(s):  
Surajit Jana ◽  
Tania Pape ◽  
Norbert W. Mitzel

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.


2021 ◽  
Vol 3 ◽  
pp. 119-127
Author(s):  
G.M. Baisarov ◽  
◽  
S.M. Adekenov ◽  

The reaction of 5-hydroxy-7-methoxy-2-phenylchroman-4-one with dibromoalkanes in acetone in the presence of potassium carbonate proceeds according to the Michael’s retro-reaction O-alkylation and leads to the formation of the corresponding 2-(bromo-alkoxy) chalcones. The structure of the synthesized compounds was confirmed by IR-, 1H- and 13C-NMR spectroscopy. The cytotoxic, hepatoprotective and anti-inflammatory effects of chalcone derivatives (2-3) were studied for the first time in vitro and in vivo.


2021 ◽  
Author(s):  
Justin J. Kosalka

This work was aimed at exploring bio-based materials for the purpose of toner production on an industrial scale. Polyester and polyether based resins were prepared in good yields from naturally occurring phenolic compounds with desired thermal and physical properties. Phenols with varying functionality such as guaiacol, eugenol and vanillin along with two synthetically produced phenolic compounds modelling the β-O-4 linkage found in softwood lignins were explored as suitable precursors to synthetic, "green", resins. Phenols were transformed into diols using glycerine carbonate and a base catalyzed reaction. Diols were then polymerized with dicarboxylic acids in an acid catalyzed, transesterfication, reaction. A novel, bio-based polyether was synthesized in one pot, one step polymerization using vanillin. Thermal properties ((Tg) and (Ts) of resulting resins were evaluated. Resulting compounds and polymers were characterized using 1H and 13C NMR spectroscopy, high resolution mass spectrometry, elemental analysis, X-ray crystallography, DSC and GPC.


2019 ◽  
Vol 31 (10) ◽  
pp. 2357-2360
Author(s):  
Jagvir Singh ◽  
Anuradha ◽  
Pradeep Kumar ◽  
Mordhwaj ◽  
Ravi Kumar

Co(II), Ni(II) and Cu(II) metal complexes of a novel Schiff base ligand (SBL) derived from condensation of 2-(4-fluorophenyl)prop-2-enaln and ethane-1,2-diamine were synthesized. All the complexes were characterized by elemental analyses, IR, UV-visible spectroscopy, magnetic susceptibility and conductance measurements and 1H NMR. From the elemental analysis data, 1:1 [M]:[ligand] metal chloride complexes are formed having the general composition [M(SBL)Cl2] and [Cu(SBL)] Cl2, [where M = Co(II), Ni(II) and SBL= {bis-2-(4-fluorophenyl)prop-2-enaln}ethane-1,2-diamine]. The result showed that the ligand is coordinated to the metal ions in a neutral tetradentate manner with ON donor sites and the nature of metal-ligand bonding can range from covalent to ionic. Antimicrobial activities of the newly synthesized chemical compounds were evaluated against Staphylococcus aureus (ATCC 25923), Staphylococcus aureus (ATCC 3160), Cabdida albicans (ATCC 227) and Staphylococcus cereviscae (ATCC 361) species and found that metal complexes exhibited more antimicrobial properties so they are more potential and significant than the ligand.


Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 174
Author(s):  
Xianghui Li ◽  
Tongxin Hu ◽  
Jiacun Wei ◽  
Yuhua He ◽  
Abualgasim Elgaili Abdalla ◽  
...  

Staphylococcus aureus phage Henu2 was isolated from a sewage sample collected in Kaifeng, China, in 2017. In this study, Henu2, a linear double-stranded DNA virus, was sequenced and found to be 43,513 bp long with 35% G + C content and 63 putative open reading frames (ORFs). Phage Henu2 belongs to the family Siphoviridae and possesses an isometric head (63 nm in diameter). The latent time and burst size of Henu2 were approximately 20 min and 7.8 plaque forming unit (PFU)/infected cells. The Henu2 maintained infectivity over a wide range of temperature (10–60 °C) and pH values (4–12). Phylogenetic and comparative genomic analyses indicate that Staphylococcus aureus phage Henu2 should be a new member of the family of Siphoviridae class-II. In this paper, Phage Henu2 alone exhibited weak inhibitory activity on the growth of S. aureus. However, the combination of phage Henu2 and some antibiotics or oxides could effectively inhibit the growth of S. aureus, with a decrease of more than three logs within 24 h in vitro. These results provide useful information that phage Henu2 can be combined with antibiotics to increase the production of phage Henu2 and thus enhance the efficacy of bacterial killing.


2015 ◽  
Vol 64 (2) ◽  
pp. 137-142 ◽  
Author(s):  
LUKASZ KROKOWICZ ◽  
HANNA TOMCZAK ◽  
ADAM BOBKIEWICZ ◽  
JACEK MACKIEWICZ ◽  
RYSZARD MARCINIAK ◽  
...  

The incidence rate of the infected and complex wound is established at approximately 40,000/1 million of the world's adult population. The aim of this study was to assess the efficiency of three novel types of wound dressings comprising sodium chloride, metatitanic acid and silicon dioxide nanoparticles. The study design was to prove their antimicrobial properties against the microorganisms most commonly causing wound infections. The study evaluated the antimicrobial effect of tested dressings on referenced strains of bacteria (ATCC collection, Argenta, Poland) and strains of fungi species (our own collection of fungi cultured from patients). The dressings were tested with both bacterial and fungal strains on solid media (Mueller-Hinton, Sobouraud, bioMerieux, France) in the standard method. The results confirmed the inhibition of growth of bacteria and revealed zones of inhibition for Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. Significant zones of inhibition were established for Staphylococcus aureus and for fungi species of the Candida sp. These results would be crucial due to the fact of the low availability of antifungal therapeutics for both systemic and topical usage. Moreover, the current standard of antifungal treatment is associated with high costs and high toxicity in general. The preliminary results are very promising but further studies are necessary. Based on the obtained results, the tested dressings may contribute to the development of the surgical armamentarium of complex wound management in the near future.


2021 ◽  
Vol 7 (1) ◽  
pp. 01-05
Author(s):  
Jikia Maia

The antimicrobial activity of filling materials was studied to improve the quality of treatment of complicated caries in vitro. Resorcin-formalin cement Resodont (“Latus”, Ukraine) - № 1; Endocort zinc oxide-eugenol cement (“Latus”, Ukraine) - No. 2; materials based on zinc oxide eugenol cement with dexamethasone: Endomethasone ivory (Septodont, France) - No. 3 and Endofil ("Produit Dentaires SA", Switzerland) - No. 4. To assess the antimicrobial activity of the studied materials, test microorganism strains were used: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 6783, Candida albicans ATCC 885-653. As a result of the study, it was established that filling materials have different antimicrobial activity. Resodont has the greatest antimicrobial activity on the test culture. Endomethason is active in relation to the test cultures studied, inferior to Resodont in its antimicrobial properties. Endocort and Endofil have less antimicrobial activity than Resodont and Endomethason, but have approximately equal growth retardation rates. It should be noted that with respect to Staphylococcus aureus, Endocort was found to be almost 1.5 times more active than Endofil. The conducted studies confirm that the materials for filling of root canals by Resodont and Endocort (Latus, Ukraine) have a pronounced antibacterial effect. They are competitive with foreign sealers and are the materials of choice, having a significantly lower cost.


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

A neutral octahedral mononuclear iron(II) tetrabromide complex, [Fe(Hampy)<sub>2</sub>Br<sub>4</sub>], that consists of equatorial bromide and protonated aminopyrazinium axial ligands is successfully synthesised through redox chemistry and analysed using X-ray crystallography. The iron(II) oxidation state is balanced by the protonated pyrazinium nitrogen just outside the coordination sphere. The biological properties of this and two other related complexes are investigated using both Gram-negative and Gram-positive bacteria as well as methicillin resistant strains. They all exhibit some antimicrobial properties albeit at moderate to poor concentrations. However, the tetrahalide complexes analysed exhibit excellent anti biofilm properties well below cytotoxic levels.


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