Tandem use of X-ray crystallography and mass spectrometry to obtain ab initio the complete and exact amino acids sequence of HPBP, a human 38-kDa apolipoprotein

2007 ◽  
Vol 71 (4) ◽  
pp. 1708-1720 ◽  
Author(s):  
Hélène Diemer ◽  
Mikael Elias ◽  
Frédérique Renault ◽  
Daniel Rochu ◽  
Carlos Contreras-Martel ◽  
...  
2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.


Author(s):  
Christopher Antony Ramsden ◽  
Wojciech Piotr Oziminski

AbstractBased on structures determined by X-ray crystallography, ab initio MP2 calculations on type A mesoionic rings give geometries in good agreement with observed values. A study of four mesoionic ring systems, each with exocyclic oxygen, nitrogen or carbon groups, shows that the presence and configuration of exocyclic lone pairs significantly influences the geometry and configurational preference. Using a localised bond model and NBO analysis, these effects are rationalised in terms of an anomeric interaction of lone pairs with the antibonding orbitals of adjacent σ bonds. In agreement with experiment, similar effects are calculated for pyran-2-imines.


2010 ◽  
Vol 63 (19) ◽  
pp. 3335-3347 ◽  
Author(s):  
Sanjit Konar ◽  
Kevin Gagnon ◽  
Abraham Clearfield ◽  
Charles Thompson ◽  
Jennifer Hartle ◽  
...  

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.


2016 ◽  
Vol 45 (30) ◽  
pp. 12206-12214 ◽  
Author(s):  
Marco Caterino ◽  
Ariel A. Petruk ◽  
Alessandro Vergara ◽  
Giarita Ferraro ◽  
Daniela Marasco ◽  
...  

Mass spectrometry, Raman microspectroscopy, circular dichroism and X-ray crystallography have been used to investigate the reaction of CO-releasing molecule Cs2IrCl5CO with the model protein RNase A.


2019 ◽  
Vol 20 (3) ◽  
pp. 520 ◽  
Author(s):  
Giarita Ferraro ◽  
Tiziano Marzo ◽  
Maria Cucciolito ◽  
Francesco Ruffo ◽  
Luigi Messori ◽  
...  

Stable five-coordinate Pt(II) complexes have been highlighted as a promising and original platform for the development of new cytotoxic drugs. Their interaction with proteins has been scarcely studied. Here, the reactivity of the five-coordinate Pt(II) compound [Pt(I)(Me) (dmphen)(olefin)] (Me = methyl, dmphen = 2,9-dimethyl-1,10-phenanthroline, olefin = dimethylfumarate) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) has been investigated by X-ray crystallography and electrospray ionization mass spectrometry. The X-ray structures of the adducts of RNase A and HEWL with [Pt(I)(Me)(dmphen)(olefin)] are not of very high quality, but overall data indicate that, upon reaction with RNase A, the compound coordinates the side chain of His105 upon releasing the iodide ligand, but retains the pentacoordination. On the contrary, upon reaction with HEWL, the trigonal bi-pyramidal Pt geometry is lost, the iodide and the olefin ligands are released, and the metal center coordinates the side chain of His15 probably adopting a nearly square-planar geometry. This work underlines the importance of the combined use of crystallographic and mass spectrometry techniques to characterize, in detail, the protein–metallodrug recognition process. Our findings also suggest that five-coordinate Pt(II) complexes can act either retaining their uncommon structure or functioning as prodrugs, i.e., releasing square-planar platinum complexes as bioactive species.


2016 ◽  
Vol 71 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Aissa Chibani ◽  
...  

AbstractThree benzoindolizine derivatives, 1, 2, and 3, were obtained via 1,3-dipolar cycloaddition. The reaction of 1-(2′-benzimidazolylmethyl)isoquinolinium ylides with dimethyl acetylenedicarboxylate gave a mixture of pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (1) and 1,10b-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (2) derivatives containing a benzimidazole moiety. The reaction of this isoquinolinium N-ylide with dimethyl maleate gave an unexpected 2,3-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (3). The structures of all reported compounds have been examined by X-ray crystallography, mass spectrometry, and NMR spectroscopy.


Molbank ◽  
10.3390/m1025 ◽  
2018 ◽  
Vol 2018 (4) ◽  
pp. M1025
Author(s):  
William Henderson ◽  
Ashwin Nair ◽  
Nathan Halcovich ◽  
Edward Tiekink

The tris(2-cyanoethyl)phosphine (tcep) complex [RuCl2{P(CH2CH2CN)3}(η6-p-cymene)] (p-cymene = p-CH3C6H4iPr) was synthesised by the bridge-splitting reaction of the chlorido-dimer [RuCl2(η6-p-cymene)]2 with tcep. The complex was characterised by a single-crystal X-ray structure determination as well as NMR spectroscopy, ESI mass spectrometry, and microelemental analysis. X-ray crystallography shows the ruthenium atom is coordinated by p-cymene in a η6-fashion, two chlorides and the phosphorus atom of the tcep ligand with the donor set defining a distorted octahedral geometry. The ESI mass spectrometry study reveals that the complex readily forms negative ions [M + Cl]− and [2M + Cl]− by association with a chloride ion.


2017 ◽  
Vol 70 (12) ◽  
pp. 1269
Author(s):  
Steven Gareth Williams ◽  
Mohan Bhadbhade ◽  
Roger Bishop ◽  
Alison Thavary Ung

The reaction of (–)-β-pinene with KCN under a mild bridged Ritter reaction gave (1S,5R,6S)-2,2,6-trimethyl-3-aza-bicyclo[3.3.1]non-3-en-6-yl acetate that subsequently reacted to provide an unexpected (1S,4R,5R,6S)-4-cyano-2,2,6-trimethyl-3-azabicyclo[3.3.1]nonane-6-yl acetate. The structure of the compound was determined by high-resolution mass spectrometry, and IR and NMR spectroscopy and confirmed by single crystal X-ray crystallography. The compound crystallises in the monoclinic P21 space group, with unit cell parameters a 8.6120 (17), b 7.4570 (15), c 11.189 (2) Å, and β 110.16 (3)°.


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