- Light-Triggered Nitric Oxide Release by a Photosensitizer to Combat Bacterial Biofilm Infections
-
Bacterial biofilms are a serious global health concern, often responsible for persistent infections. New strategies to prevent and treat bacterial infections by eradication of the biofilms are urgently needed. A novel ruthenium-based compound is reported in this study that functions as both a boronic acid-decorated photosensitizer (PS) and a light-triggered nitric oxide (NO) releasing agent. The compound can selectively attach to the bacterial membrane and biofilms and it is highly potent at eradicating Pseudomonas aeruginosa biofilms through the simultaneous release of NO and reactive oxygen species (ROS). The compound, which is more effective than clinical antibiotic tobramycin, also has excellent bacterial specificity and shows no significant cytotoxicity to human cells. The results reveal potential applications of this innovative dual-functional photoactivated ruthenium compound to combat bacterial biofilm infections.
- Zhao, Zhennan,Li, Huinan,Tao, Xuan,Xie, Yanxuan,Yang, Liang,Mao, Zong-Wan,Xia, Wei
-
-
Read Online
- Cooperative catalysis with aldehydes and copper: Development and application in aerobic oxidative C-H amination at room temperature
-
A conceptually new cooperative catalytic system via a synergistic combination of aldehyde and copper catalysis has been established based on systemic mechanistic studies. This new cooperative catalysis has been successfully applied in the direct aerobic oxidative C-H amination of azoles at room temperature, which was previously realized under harsh conditions. Mechanistic studies including isotopic labeling experiments and kinetic isotope effect (KIE) experiments support a reaction pathway that involves formation of an aminal, hydrolysis of the aminal to generate the copper-amide species, subsequent C-H amination and re-oxidation of copper(I) to copper(II) by oxygen. It not only provides an efficient method to realize the oxidative C-H amination of benzoxazoles with free amines at room temperature, but also paves the way for establishing new C-N bond formation reactions by using this efficient cooperative catalysis. Copyright
- Xie, Yinjun,Qian, Bo,Xie, Pan,Huang, Hanmin
-
supporting information
p. 1315 - 1322
(2013/06/27)
-
- Synthesis of α-amino acids through samarium(II) iodide promoted reductive coupling of nitrones with CO2
-
Several N-benzylnitrones reacted with carbon dioxide in the presence of samarium(II) iodide leading to α-amino acids as the products of reductive C-C coupling. The best selectivities were observed at a carbon dioxide pressure of 50 bar at ambient temperature. The influences of different functional groups in the nitrone backbone and of the coordinating additives to samarium(II) iodide on the product distribution were investigated. The racemic α-amino acids were obtained in up to 70% yield based on HPLC data. A novel approach to the synthesis ofα-amino acids is disclosed, involvingC-carboxylation of nitrones by gaseous CO2 under reductive coupling reaction conditions (SmI2, 0.1 M in THF) at ambient temperature and 50 bar of CO 2 pressure. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- Prikhod'Ko, Alexander,Walter, Olaf,Zevaco, Thomas A.,Garcia-Rodriguez, Jaime,Mouhtady, Omar,Py, Sandrine
-
supporting information; experimental part
p. 3742 - 3746
(2012/09/25)
-
- The interplay of secondary Hg...S, Hg...N and Hg...π bonding interactions in supramolecular structures of phenylmercury(ii) dithiocarbamates
-
Three new phenylmercury(ii) and one mercury(ii) dithiocarbamate complexes viz. PhHg S2CN(PyCH2)Bz (1), PhHg S 2CN(PyCH2)CH3 (2), PhHg S2CN(Bz) CH3 (3), and [Hg (NCS2(PyCH2)Bz)2] (4) (Py = pyridine; Bz = benzyl) have been synthesized and characterized by elemental analyses, IR, electronic absorption, 1H and 13C NMR spectroscopy. The crystal structures of 1, 2 and 3 showed a linear S-Hg-C core at the centre of the molecule, in which the metal atom is bound to the sulfur atom of the dithiocarbamate ligand and a carbon atom of the aromatic ring. In contrast the crystal structure of 4 showed a linear S-Hg-S core at the Hg(ii) centre of the molecule. Weak intermolecular Hg...N (Py) interactions link molecules into a linear chain in the case of 1, whereas chains of dimers are formed in 2 through intermolecular Hg...N (Py) and Hg...S interactions. 3 forms a conventional face-to-edge dimeric structure through intermolecular Hg...S secondary bonding and 4 forms a linear chain of dimers through face-to-face Hg...S secondary bonding. In order to elucidate the nature of these secondary bonding interactions and the electronic absorption spectra of the complexes, ab initio quantum chemical calculations at the MP2 level and density functional theory calculations were carried out for 1-3. Complexes 1 and 2 exhibited photoluminescent properties in the solid state as well as in the solution phase. Studies indicate that Hg...S interactions decrease and Hg...N interactions increase the chances of photoluminescence in the solid phase The Royal Society of Chemistry 2011.
- Singh, Vikram,Kumar, Abhinav,Prasad, Rajendra,Rajput, Gunjan,Drew, Michael G. B.,Singh, Nanhai
-
p. 6817 - 6826
(2012/04/11)
-
- Aminophosphinic acids in a pyridine series, Part 2: Synthesis of 2-, 3-, and 4-pyridyl derivatives of 1-(Benzylamino)-methyl-H-phosphinic Acids
-
New 2-pyridyl, 3-pyridyl, and 4-pyridyl derivatives of 1-[N-(benzyl)amino]- methyl-H-phosphinic acid were prepared by the addition of bis(trimethylsilyl) phosphonite to the corresponding imines and subsequent methanolysis of the addition products. Treatment of the 2-pyridyl- and 1-(4-pyridyl)-1-(benzylamino) -methyl-H-phosphinic acids with aqueous mineral acids leads to cleavage and formation of the corresponding secondary amines and phosphorous acid (H3PO3).
- Goldeman, Waldemar,Boduszek, Bogdan
-
experimental part
p. 1413 - 1425
(2010/03/24)
-
- A general one-step synthesis of multidentate (pyridylalkyl)amines from mono-, bis-, tris- and tetrakis(bromomethyl)benzenes: Potential ligands for supramolecular assembly
-
The synthesis of new multidentate nitrogen-containing ligands is of ongoing interest. In this report, the one-step syntheses of a series of (pyridylalkyl)amine derivatives is described. The reported compounds contain both pyridine rings and sp3-hybridized nitrogen as potential donor sites. The general synthetic method involves a room temperature reaction of mono-, bis-, tris-, or tetrakis(bromomethyl)benzenes with an excess of (pyridylmethyl)amine in tetrahydrofuran. The products can be purified by distillation, chromatography or recrystallization and are obtained in fair to good yields. The advantages of this synthetic method are the procedural simplicity and the ready availability of the starting materials. The applicability of these compounds in supramolecular chemistry is demonstrated by the reaction of two of the described ligands with silver(I) salts. Georg Thieme Verlag Stuttgart.
- Sengupta, Parbati,Henkes, Amanda E.,Kumar, Mananjali K.,Zhang, Hongming,Son, David Y.
-
-
- Aminophosphinic acids in a pyridine series: Cleavage of pyridine-2- and pyridine-4-methyl(amino)phosphinic acids in acidic solutions
-
The synthesis of a series of new pyridine aminomethylphosphinic acids is described. These compounds were obtained in the reaction of the corresponding pyridine aldehydes with primary amines and with ethyl phenylphosphinate, or methylphosphinate, in the presence of bromotrimethylsilane. In aqueous, strong acid solutions, pyridine aminophosphinic acids were split, forming the phenyl-, or methylphosphonic, acid and the corresponding secondary pyridyl-alkylamines. The kinetics of some observed cleavages were measured, and a mechanism of the cleavage has been proposed. Copyright Taylor & Francis Group, LLC.
- Boduszek, Bogdan,Olszewski, Tomasz,Goldeman, Waldemar,Konieczna, Magdalena
-
p. 787 - 795
(2007/10/03)
-
- Aminophosphine oxides in a pyridine series. Studies on the cleavage of pyridine-2- and pyridine-4-yl-(N-benzylamino)-methyldiphenylphosphine oxides in acidic solutions
-
The synthesis and reactions of 1-(N-benzylamino)-1-(2-pyridyl)- and 1-(N-benzylamino)-1-(4-pyridyl)-methyldiphenylphosphine oxides are described. It was found that these compounds were exceptionally easy to cleave in aqueous sulfuric acid solutions to form diphenylphosphinic acid and the corresponding N-(pyridylmethyl)-benzylamines. The structure of a single diastereoisomer, that is, the (R)-(+)-1-[N-(α-methylbenzylamino)]-1-(4-pyridyl)-(S)-methyldiphen ylphosphine oxide was determined by X-ray crystallography. The acidic alcoholysis of the selected model chiral pyridine aminophosphine oxides was investigated by means of 31P NMR spectroscopy. The cleavage kinetics were also studied. On the basis of the obtained results, a mechanism of the cleavage was formulated.
- Goldeman, Waldemar,Olszewski, Tomasz K.,Boduszek, Bogdan,Sawka-Dobrowolska, Wanda
-
p. 4506 - 4518
(2007/10/03)
-
- A Simple Synthesis of Pyridine Aminophosphinic Acids and Pyridine Aminophosphine Oxides. The Unusual Cleavage of Pyridylmethyl-(N-benzylamino)-phenylphosphinic Acids and Phosphine Oxides in Acidic Solutions
-
Pyridine aminophosphinic acids were synthesized in reaction, of N-(benzyl)-pyridylmethylimines with ethyl phenylphosphinate, in the presence of bromotrimethylsilane. Pyridine aminophosphine oxides were obtained in excellent yields by treatment of the corresponding imines with diphenylphosphine oxide. Among these compounds, the 2-pyridyl and 4-pyridyl derivatives were subject to a simple cleavage in aqueous mineral acid solutions. Products of the cleavages were N-(pyridylmethyl)benzylamines and phenylphosphonic (or diphenylphosphinic) acid, respectively.
- Boduszek, Bogdan
-
p. 4087 - 4094
(2007/10/03)
-
- The acidic cleavage of pyridylmethyl(amino)phosphonates. Formation of the corresponding amines
-
Hydrolysis of 3-pyridylmethyl(amino)phosphonates by means of 20% aq. hydrochloric acid gave corresponding 3-pyridimethyl(amino)phosphonic acids, as expected. However, hydrolysis of 2- and 4-pyridylmethyl(amino)phosphonates led to decomposition of the phosphonates with a cleavage of C-P bond and formation of the corresponding amines. The leaving phosphorus moiety was identified as phosphoric acid. The scope of the reaction is limited to 2- and 4-pyridylmethyl derivatives of aminophosphonic acids and their esters, as well as to the derivatives possessing similar structure. On the contrary, the basic hydrolysis of 2- and 4-pyridylmethyl(amino)phosphonates led to the corresponding monoalkyl esters of the aminophosphonates, and no cleavage of C-P bond was observed in those cases.
- Boduszek, Bogdan
-
p. 12483 - 12494
(2007/10/03)
-
- 1-aminophosphonic acids and esters bearing heterocyclic moiety. Part 2. 1 pyridine, pyrrole and emidazole derivatives
-
The benzylic amines (benzylamine, benzhydrylamine and benzyl carbamate) were applied in the synthesis of aminophosphonates derived from pyridine, pyrrole and imidazole. The Schiff bases obtained from corresponding heterocyclic aldehydes and benzylic amines were caused to react with diphenyl phosphorate or dibenzyl phosphonate to form corresponding heterocyclic aminophosphonates in good yields. The N-(benzylamino)-phosphonates were deblocked by catalytic hydrogenolysis. The benzhydryl group from the phosphonates was removed by acidic hydrolysis, and the carbobenzyloxy group from the phosphonates can be easy removed by treatment with a solution of 30% HBr in acetic acid, as well. It was found that during acidic hydrolysis of 2-and 4-pyridylmethylaminophosphonates a rearrangement occurred, combined with a cleavage of C-P bond in the phosphonate molecules and subsequent formation of the corresponding amines.
- Boduszek, Bogdan
-
p. 209 - 218
(2007/10/03)
-
- Ligand-to-Ligand charge-transfer photochemistry
-
The photochemistry and photophysics are reported for a unique series of complexes of the type fac-(bpy)-ReI(CO)3 -(α-AA), where bpy=2,2′-bipyridine and α-AA is a "reactive donor ligand" that incorporates an α-amino alcohol functional
- Wang, Yinsheng,Hauser, Brian T.,Rooney, Michael M.,Burton, Richard D.,Schanze, Kirk S.
-
p. 5675 - 5683
(2007/10/02)
-