Novel chiral fluorescent chemosensors for malate and acidic amino acids based on two-arm thiourea and amide

2008 ◽  
Vol 86 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Xiao-Huan Huang ◽  
Yong-Bing He ◽  
Zhi-Hong Chen ◽  
Chen-Guang Hu ◽  
Guang-Yan Qing
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
Key Words ◽  
Fluorescent Chemosensors ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Acidic Amino Acids ◽  
Recognition Ability

The charge neutral anthracene based chiral fluorescent receptors 4a and 4b containing thiourea and amide groups were synthesized by simple steps in good yields, and their enantioselective recognition for chiral dicarboxylic anions (L/D-malate, L/D-aspartate, and L/D-glutamate) were examined by UV–vis, fluorescence, and 1H NMR spectroscopy. The sensor 4a exhibited an excellent enantioselective recognition ability towards malate (Kass (L)/Kass (D) = 9.65).Key words: enantioselective recognition, chiral chemosensor, fluorescence, malate.

Enantioselective fluorescent sensors for chiral carboxylates based on BINOL — Synthesis and chiral recognition

2010 ◽  
Vol 88 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Kuo-xi Xu ◽  
Yu-xia Wang ◽  
Shu-yan Jiao ◽  
Jin Zhao ◽  
Chao-jie Wang
Keyword(s):  
Nmr Spectroscopy ◽  
Chiral Recognition ◽  
Fluorescent Sensors ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Recognition Ability ◽  
Chiral Materials ◽  
Fluorescent Recognition ◽  
Derivatives Of ◽  
C Nmr

The four novel derivatives of 1,1′-bi-2-naphthol (BINOL) have been prepared, and the structures of these compounds have been characterized by IR, MS, 1H and 13C NMR spectroscopy, and elemental analysis. The enantioselective recognition of these receptors has been studied by fluorescence titration and 1H NMR spectroscopy. The receptors exhibited different chiral-recognition abilities towards some enantiomers of chiral materials and formed 1:1 complexes between host and guest. The receptors exhibit excellent enantioselective fluorescent-recognition ability towards the amino acid derivatives.

scholarly journals The Differential Metabolic Profiles Between Deltamethrin-Resistant and -Susceptible Strains of Aedes albopictus (Diptera: Culicidae) by 1H-NMR

2020 ◽  
Author(s):  
Lianfen Huang ◽  
Jun Li ◽  
Lilan Peng ◽  
Ruili Xie ◽  
Xinghua Su ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Sugar Metabolism ◽  
Enzyme Synthesis ◽  
Metabolomic Analysis ◽  
Biochemical Responses ◽  
Acidic Amino Acids ◽  
Physiological And Biochemical

Abstract Metabolomics can indicate the physiological and biochemical responses of mosquitoes to different stimulants, including insecticides, which allow them to adapt to different inhospitable environments. Though metabolic differences between insecticide-resistant and -susceptible strains have been established for other mosquito species, such as Anopheles and Culex, it is yet to be done for Aedes albopictus (Skuse). In this study, nuclear magnetic resonance (NMR) spectroscopy–based metabolomic analysis performed on Ae. albopictus deltamethrin-resistant and -susceptible strains showed significant differences in amino acid, organic acid, and sugar metabolism. Concentrations of neutral amino acids and sugars tended to be lower in the deltamethrin-resistant strain than in the deltamethrin-suceptible strain, but the concentration of basic and acidic amino acids and organic acids increased. All these changes might accommodate biochemical and physiological needs in deltamethrin-resistant mosquitoes, such as enzyme synthesis and detoxification. This was further confirmed by the predictable draft metabolic map. This is the first report using NMR spectroscopy to investigate the metabolic differences between deltamethrin-resistant and -susceptible strains of Ae. albopictus. To a certain degree, this demonstrates how Ae. albopictus develop insecticide resistance by metabolic reprograming to survive under the insecticide pressure.

Reaction of Hypochlorous Acid with Bovine Nasal Cartilage Comparison to Pig Articular Cartilage

1997 ◽  
Vol 52 (9-10) ◽  
pp. 694-701 ◽  
Author(s):  
Jürgen Schiller ◽  
Jürgen Arnhold ◽  
Annett Zachäus ◽  
Arnold Klaus
Keyword(s):  
Amino Acids ◽  
Nuclear Magnetic Resonance ◽  
Articular Cartilage ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Phosphate Buffer ◽  
Hypochlorous Acid ◽  
Proton Nuclear Magnetic Resonance ◽  
Nasal Cartilage ◽  
H Nmr

The action of sodium hypochlorite (NaOCl) on bovine nasal cartilage was studied by proton nuclear magnetic resonance (1H-NMR) spectroscopy in order to model degradation processes of cartilage caused by neutrophil-derived hypochlorous acid.Nasal cartilage was chosen as a mean of comparison because it differs from articular cartilage in its composition. It contains some more proteoglycans, i.e. polymeric carbohydrates and less collagen than articular cartilage. This is important for studying the influence of hypochlorous acid on cartilage components (collagen and polysaccharides). Cartilage samples were incubated at 37 °C with phosphate buffer in the presence or absence of NaOCl. Supernatants were collected and assayed by NMR-spectroscopy. In the presence of pure phosphate buffer, the supernatants of bovine nasal cartilage were less rich in low molecular mass metabolites (e.g. amino acids, lactate) than articular cartilage. However, intense signals for highly mobile N acetyl groups of cartilage polysaccharides were detectable in nasal cartilage.NaOCl caused an increase in signals for acetate and formiate. Signals for N-acetyl groups rose only during the first 25 minutes of incubation with NaOCl. Then, their concentration decreased markedly. These changes were related to an enhanced release of Chondroitinsulfate from nasal cartilage

Chiral Aryl Sulfonyl Hydantoins as Hypoglycemic Agents

2000 ◽  
Vol 55 (2) ◽  
pp. 203-207 ◽  
Author(s):  
Roshan Ahmad ◽  
Rukhsana Jabeen ◽  
Mohammad Zia-ul-Haq ◽  
Humaira Nadeem ◽  
Helmut Duddeck ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
Hypoglycemic Agents ◽  
Antidiabetic Activity ◽  
H Nmr ◽  
Hydantoin Derivatives

Some novel chiral sulfonyl hydantoin derivatives 2a-e and 3 a-e have been prepared. p-Toluenesulfonyl chloride on treatment with L-amino acids in presence of K2CO3/H2O yielded N-(p-toluensulfonyl-)amino acids 1a - e which were cyclized in presence of NH4-SCN Ac2O to afford 1-(p-toluenesulfonyl)-5-substituted-2-thiohydantoins 2a-e. These compounds were oxidized with HNO3 to yield 1-(p-toluenesulfonyl)-5-substituted hydantoins 3a-e. The enantiomeric ratios of 3a-e were determined by 1H NMR spectroscopy using Eu(hfc)3. The antidiabetic activity of 3a-d has been determined.

scholarly journals The Binding Behaviors between Cyclopentanocucurbit[6]uril and Three Amino Acids in the Solid and the Solution Phases

2020 ◽  
Author(s):  
Si Yuan Cheng ◽  
Wei Wei Zhao ◽  
Xi Nan Yang ◽  
Lian Tong Wei ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
Self Assembly ◽  
Titration Calorimetry ◽  
Carboxyl Group ◽  
X Ray ◽  
Alkyl Chains ◽  
X Ray Crystallography ◽  
H Nmr ◽  
External Conditions

Abstract Binding behaviors between CyP 6 Q[6] and three have been investigated by means of X-ray crystallography, 1 H NMR spectroscopy,amino acids and isothermal titration calorimetry (ITC). The results showed that CyP 6 Q[6] forms a 1:2 inclusion complex with glycine, but 1:1 complexes with both leucine and lysine. Whereas the carboxyl group of glycine can enter the interior of the cavity of CyP6Q[6], only the alkyl chains of leucine and lysine can enter this cavity. Interestingly, leucine can adopt two different self-assembly modes upon its interaction with cucurbituril, depending on the external conditions, whereas glycine and lysine do not exhibit such behavior.

scholarly journals Synthesis of homochiral zeolitic metal–organic frameworks with amino acid and tetrazolates for chiral recognition

RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 4872-4875 ◽  
Author(s):  
Min-Yu Li ◽  
Fei Wang ◽  
Zhi-Gang Gu ◽  
Jian Zhang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chiral Recognition ◽  
Metal Organic Frameworks ◽  
Enantioselective Recognition ◽  
Recognition Ability ◽  
Metal Organic

By mixing amino acids and tetrazolate ligands, a series of homochiral zeolitic metal–organic frameworks (ZMOFs) with ABW topology have been synthesized, which show permanent microporosity and potential enantioselective recognition ability.

Reactions of silanes with bis(cyclopentadienyl)dialkylzirconium complexes

1991 ◽  
Vol 69 (2) ◽  
pp. 264-276 ◽  
Author(s):  
Ying Mu ◽  
Clare Aitken ◽  
Bruno Cote ◽  
John F. Harrod ◽  
Edmond Samuel
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Nmr Spectroscopy ◽  
Key Words ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Active Catalyst ◽  
Systematic Comparison ◽  
H Nmr ◽  
Cyclic Polymer

A systematic comparison between the dimethylzirconocene (DMZ) and dimethyltitanocene (DMT) catalyzed dehydrocoupling of organosilanes is reported. The polymerization rates of primary silanes are about ten times faster for DMZ than for DMT, but the characteristics of the polymers produced are essentially identical. Variations of molecular weight and molecular weight distribution with varying monomer and reaction time, and the relative amounts of linear and cyclic polymer are also essentially the same for the two catalysts.Oligomerizations of phenylmethylsilane, diphenylsilane, and 1,2-diphenyldisilane are described. The compound Cp2Zr(SiPhMeH)(μ-H)2(SiPhMe2)ZrCp2 (1b) is isolated from the reaction of phenylmethylsilane with DMZ and its structure confirmed by crystallography and 1H-NMR spectroscopy. The compound Cp2Zr(Me)(μ-H)2(SiPh2H)ZrCp2 (1d) is isolated from the reaction of diphenylsilane with DMZ and its structure assigned by NMR spectroscopy. A number of other hydride bridged species are observed by 1H-NMR in the reactions of DMZ with phenylmethyl-, diphenyl-, and n-butylmethylsilanes and their structures are tentatively assigned. The implications of these observations on the mechanism of transformation of DMZ into active catalyst and our current views of the polymerisation mechanism are also discussed. Key words: silanes, dehydrocoupling, titanocene, zirconocene, polysilanes.

Regioselectivity in SNH reactions of some 3-nitro-1,5-naphthyridines with chloromethyl phenyl sulfone

2004 ◽  
Vol 82 (5) ◽  
pp. 567-570 ◽  
Author(s):  
Maria Grzegożek ◽  
Barbara Szpakiewicz
Keyword(s):  
Nmr Spectroscopy ◽  
Nucleophilic Substitution ◽  
Key Words ◽  
High Yield ◽  
Vicarious Nucleophilic Substitution ◽  
H Nmr ◽  
Phenyl Sulfone ◽  
Convenient Synthesis ◽  
Key Words 3 ◽  
Hydrogen Substitution

3-Nitro-1,5-naphthyridine and its 2-substituted derivatives react with the carbanion of chloromethyl phenyl sulfone to give hydrogen-substitution products at position 4 in high yield. The intermediacy of 4-(phenylsulfonyl)chloromethyl σ adducts of 2-R-3-nitro-1,5-naphthyridines (R = H, D, Cl, OC2H5, NHCH3, OH) was established by 1H NMR spectroscopy. A convenient synthesis of 2-N-methylamino-3-nitro-1,5-naphthyridine is reported. Key words: 3-nitro-1,5-naphthyridines, anionic (phenylsulfonyl)chloromethyl σ adducts, vicarious nucleophilic substitution.

scholarly journals Chiral discrimination of α-hydroxy acids and N-Ts-α-amino acids induced by tetraaza macrocyclic chiral solvating agents by using 1H NMR spectroscopy

2017 ◽  
Vol 15 (7) ◽  
pp. 1642-1650 ◽  
Author(s):  
Caixia Lv ◽  
Lei Feng ◽  
Hongmei Zhao ◽  
Guo Wang ◽  
Pericles Stavropoulos ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chiral Discrimination ◽  
Hydroxy Acids ◽  
H Nmr

Several α-hydroxy acids and N-Ts-α-amino acids were effectively discriminated in the presence of tetraaza macrocyclic chiral solvating agents (TAMCSAs) 1a–1d by 1H NMR spectroscopy.

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