scholarly journals Novel ion-binding C3 symmetric tripodal triazoles: synthesis and characterization

2014 ◽  
Vol 12 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Gábor Neumajer ◽  
Gergő Tóth ◽  
Szabolcs Béni ◽  
Béla Noszál

AbstractNovel C3 symmetric tripodal molecules were synthesized from cyclohexane 1,3,5-tricarboxylic acid. Utilizing click and Sonogashira reactions, ion-binding triazole and pyridazin-3(2H)-one units were incorporated to form polydentate ligands for ion complexation. The structures of the novel C3 symmetric derivatives were extensively characterized by 1H, 13C and 2D NMR techniques along with HRMS and IR. The copper(I)-binding potentials of these ligands were investigated by using them as additives in model copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) reactions. The copper(I) complexation ability of our compound was also proved by different spectroscopic methods, such as mass spectrometry, UV and NMR spectroscopy. Based on the mass spectrometric data all of the C3 symmetric ligands formed 1:1 complex with copper(I) ion. The specific role of C3 symmetric polydentate form in the complexation process was also discussed

2018 ◽  
Vol 20 (5) ◽  
pp. 3381-3387 ◽  
Author(s):  
Kota Katayama ◽  
Yuji Furutani ◽  
Masayo Iwaki ◽  
Tetsuya Fukuda ◽  
Hiroo Imai ◽  
...  

ATR-FTIR spectroscopic study elucidates the novel role of Cl−-binding in primate long-wavelength-sensitive (LWS) visual pigment.


2008 ◽  
Vol 8 (4) ◽  
pp. 2096-2101 ◽  
Author(s):  
Claudio Evangelisti ◽  
Patrizio Raffa ◽  
Federica Balzano ◽  
Gloria Uccello Barretta ◽  
Giovanni Vitulli ◽  
...  

Pt nanoclusters have been generated by reaction of Pt vapour and mesitylene vapour and the role of the mesitylene/platinum ratio and the Pt particle size has been evaluated, quenching the resulting mesitylene solvated Pt atoms with 1,3-divinyltetramethyldisiloxane (DVS) as additional ligand. The Pt particle sizes have been estimated on the basis of DOSY (Diffusion-Ordered SpectroscopY) analysis and information on their structure features have been obtained by combined use of 2D NMR techniques.


2012 ◽  
Vol 32 (2) ◽  
pp. 239
Author(s):  
Rosica P. Nikolova ◽  
Boris Shivachev ◽  
Bozhana Mikhova ◽  
Bistra Stamboliyska ◽  
Kristina Mladenovska ◽  
...  

In this paper, the synthesis and structure of a novel pyrano[3,2-c]coumarin, which was obtained unexpectedly in a reaction of phosphoryl chloride and acenocoumarol, are presented. The chemical structure of the novel compound was elucidated by a detailed spectroscopic analysis based mainly on 1D and 2D NMR techniques. The structure was finally confirmed with a single-crystal X-ray analysis. The B3LYP/6-311+G** method correctly reproduces the bond lengths, bond angles, torsion angles, and other experimental spectroscopic data, which can be useful for investigating the characteristics of some structurally related molecules. Additionally, the title compound was obtained in high yields by performing a dehydratation reaction of acenocuomarol with acetic anhydride.  


2006 ◽  
Vol 1 (7) ◽  
pp. 1934578X0600100 ◽  
Author(s):  
Qianliang Chen ◽  
Wenji Sun ◽  
Guangzhong Tu ◽  
Zhangyan Shi ◽  
Yongmin Zhang

A novel amide, qinjiaoamide and a novel iridoid, erythrocentaurin acid, together with seven known compounds [erythrocentaurin (3), roburic acid (4), oleanolic acid (5), gentiopicroside (6), swertiamarine (7), sweroside (8), and 6′-O-β-D-glucosylgentiopicroside (9)], were isolated from the root of Gentiana macrophylla Pall. from Shaanxi Province, China. The novel compounds were identified as N-pentacosyl-2-carboxy-benzoyl amide (1) and 5-carboxyl-3,4-dihydrogen-1H-2-benzopyran-1-one (2), on the basis of spectroscopic (UV, IR, 1D- and 2D-NMR) and mass spectrometric data. Among the known compounds, erythrocentaurin (3) was isolated from the genus Gentiana for the first time.


Synthesis ◽  
2020 ◽  
Vol 52 (15) ◽  
pp. 2241-2244
Author(s):  
Martin A. Iglesias-Arteaga ◽  
Juan E. Hernández-Martínez

BF3·OEt2-catalyzed aldol reaction of steroid sapogenins with glyoxylic acid or pyruvic acid led to compounds in which the novel spirocyclic side chain bears an α,β-unsaturated lactone. The structures of the new spirolactones were established with the aid of combined 1D and 2D NMR techniques. A plausible mechanism is described.


Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.


2019 ◽  
Author(s):  
F Foerster ◽  
K Mönkemüller ◽  
PR Galle ◽  
H Neumann

Author(s):  
Vike Martina Plock

This chapter analyzes the role of fashion as a discursive force in Rosamond Lehmann’s 1932 coming-of-age novel Invitation to the Waltz. Reading the novel alongside such fashion magazines as Vogue, it demonstrates Lehmann’s awareness that 1920s fashion, in spite of its carefully stylized public image as harbinger of originality, emphasized the importance of following preconceived (dress) patterns in the successful construction of modern feminine types. Invitation to the Waltz, it argues, opposes the production of patterned types and celebrates difference and disobedience in its stead. At the same time, the novel’s formal appearance is nonetheless dependent on the very same tenets it criticizes. On closer scrutiny, it is seen to reveal its resemblance to Virginia Woolf’s To the Lighthouse (1927). A tension between imitation and originality determines sartorial fashion choices. This chapter shows that female authorship in the inter-war period was subjected to the same market forces that controlled and sustained the organization of the fashion industry.


Author(s):  
Joana Martins ◽  
Niina Leikoski ◽  
Matti Wahlsten ◽  
Joana Azevedo ◽  
Jorge Antunes ◽  
...  

Cyanobactins are a family of linear and cyclic peptides produced through the post-translational modification of short precursor peptides. Anacyclamides are macrocyclic cyanobactins with a highly diverse sequence that are common in the genus <i>Anabaena</i>. A mass spectrometry-based screening of potential cyanobactin producers led to the discovery of a new prenylated member of this family of compounds, anacyclamide D8P (<b>1</b>), from <i>Sphaerospermopsis</i> sp. LEGE 00249. The anacyclamide biosynthetic gene cluster (<i>acy</i>) encoding the novel macrocyclic prenylated cyanobactin, was sequenced. Heterologous expression of the acy gene cluster in <i>Escherichia</i> <i>coli</i> established the connection between genomic and mass spectrometric data. Unambiguous establishment of the type and site of prenylation required the full structural elucidation of <b>1</b> using Nuclear Magnetic Resonance (NMR), which demonstrated that a forward prenylation occurred on the tyrosine residue. Compound <b>1</b> was tested in pharmacologically or ecologically relevant biological assays and revealed moderate antimicrobial activity towards the fouling bacterium <i>Halomonas aquamarina</i> CECT 5000.<br>


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