scholarly journals Use of 95Mo NMR Spectroscopy as a New Approach to Structural Analysis of Diamagnetic Molybdenum Complexes

1976 ◽  
Vol 31 (5) ◽  
pp. 454-456 ◽  
Author(s):  
O. Lutz ◽  
A. Nolle ◽  
P. Kroneck
Keyword(s):  
Fourier Transform ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Oxidation States ◽  
New Approach ◽  
Molybdenum Complexes ◽  
Experimental Parameters

Abstract Fourier Transform NMR measurements of 95Mo and 97Mo are reported for several molybdenum compounds in different oxidation states. Using the molybdate ion as a reference, chemical shifts from about +500 ppm to about -1900 ppm have been observed. Experimental parameters and a chemical shift scale are given.

scholarly journals Structure of Nanobody Nb23

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3567
Author(s):  
Mathias Percipalle ◽  
Yamanappa Hunashal ◽  
Jan Steyaert ◽  
Federico Fogolari ◽  
Gennaro Esposito
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Solution Structure ◽  
Chemical Shifts ◽  
Molecular Size ◽  
Side Chain ◽  
3D Nmr ◽  
Target Antigen ◽  
Internuclear Distances ◽  
2D And 3D

Background: Nanobodies, or VHHs, are derived from heavy chain-only antibodies (hcAbs) found in camelids. They overcome some of the inherent limitations of monoclonal antibodies (mAbs) and derivatives thereof, due to their smaller molecular size and higher stability, and thus present an alternative to mAbs for therapeutic use. Two nanobodies, Nb23 and Nb24, have been shown to similarly inhibit the self-aggregation of very amyloidogenic variants of β2-microglobulin. Here, the structure of Nb23 was modeled with the Chemical-Shift (CS)-Rosetta server using chemical shift assignments from nuclear magnetic resonance (NMR) spectroscopy experiments, and used as prior knowledge in PONDEROSA restrained modeling based on experimentally assessed internuclear distances. Further validation was comparatively obtained with the results of molecular dynamics trajectories calculated from the resulting best energy-minimized Nb23 conformers. Methods: 2D and 3D NMR spectroscopy experiments were carried out to determine the assignment of the backbone and side chain hydrogen, nitrogen and carbon resonances to extract chemical shifts and interproton separations for restrained modeling. Results: The solution structure of isolated Nb23 nanobody was determined. Conclusions: The structural analysis indicated that isolated Nb23 has a dynamic CDR3 loop distributed over different orientations with respect to Nb24, which could determine differences in target antigen affinity or complex lability.

13C-Chemische Verschiebungen von Aminosäuren und Peptiden / 13C-NMR Chemical Shifts of Amino Acids and Peptides

1971 ◽  
Vol 26 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Wolfgang Voelter ◽  
Günther Jung ◽  
Eberhard Breitmaier ◽  
Ernst Bayer
Keyword(s):  
Amino Acids ◽  
Fourier Transform ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Analytical Tool ◽  
Reasonable Time ◽  
C Isotopes ◽  
Direct Recording ◽  
C Nmr

Pulse - Fourier - Transform-13C-NMR spectroscopy allowed the direct recording of 13C-NMR spectra of amino acids and peptides with natural abundance of 13C isotopes within a reasonable time. The 13C-signals of more than 50 free and protected amino acids and several peptides were assigned. 13C-NMR spectroscopy gives valuable information about the carbon skeleton, thus offering a new analytical tool for the study of biopolymers and their constituents.

A nuclear magnetic resonance investigation of the micellar properties of a series of sodium cyclohexylalkanoates

1999 ◽  
Vol 77 (11) ◽  
pp. 1994-2000 ◽  
Author(s):  
Judith A MacInnis ◽  
R Palepu ◽  
D Gerrard Marangoni
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Conformational Changes ◽  
Chemical Shifts ◽  
Micelle Formation ◽  
Counterion Binding ◽  
Micellar Properties ◽  
Aggregation Numbers ◽  
Multinuclear Nmr Spectroscopy ◽  
Magnetic Resonance Investigation

The micellar properties of a family of surfactants, the sodium cyclohexylalkanoates, have been investigated in aqueous solution using multinuclear NMR spectroscopy. C-13 chemical shift measurements have been used to determine both the cmc values and the micellar aggregation numbers (Ns values) of these surfactants. The cmc values and the degrees of counterion binding were estimated from 23Na chemical shift measurements. The critical micelle concentrations (cmc's) and the aggregation numbers determined from the NMR experiments indicate that these amphiphiles have high cmc's and low aggregation numbers when compared to other single-headed surfactants (most notably the sodium alkanoates). The conformational changes incurred by the carbon atoms upon micelle formation have been deduced from the 13C chemical shift differences (δsurf,mic - δsurf,aq). These results are used to discuss the formation of the aggregates of the sodium cyclohexylalkanoate surfactants as a function of the length of the alkanoate side chain.Key words: micelles, surfactants, NMR spectroscopy, chemical shifts, aggregation numbers, degree of counterion binding, conformational changes.

Chemical shift correlated two-dimensional nmr spectroscopy and its application to solving the proton nmr spectra of oligoribonucleotides

1980 ◽  
Vol 58 (18) ◽  
pp. 1947-1956 ◽  
Author(s):  
Alex D. Bain ◽  
Russell A. Bell ◽  
Jeremy R. Everett ◽  
Donald W. Hughes
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Nmr Spectra ◽  
Pulse Sequence ◽  
Chemical Shifts ◽  
Proton Nmr ◽  
Two Dimensional

An alternative two-dimensional nmr pulse sequence, (90°–t1/2–90°–t1/2–FID),correlates the chemical shifts of coupled nuclei. The application of this technique to the solution of the complicated proton nmr spectra of oligoribonucleotides is discussed.

scholarly journals Carbon-13 NMR Chemical Shift of Methyl Group: A Useful Parameter for Structural Analysis of C-Methylated Flavonoids

2006 ◽  
Vol 1 (11) ◽  
pp. 1934578X0600101
Author(s):  
Pawan K. Agrawal ◽  
Chandan Agrawal ◽  
Shravan Agrawal
Keyword(s):  
Structural Analysis ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Nmr Chemical Shift ◽  
Methyl Group ◽  
Nmr Chemical Shifts ◽  
Nmr Study ◽  
Pterocarpus Santalinus ◽  
Group A ◽  
C Nmr

The 13C NMR resonances corresponding to the C-Me group of C-6 and/or C-8 C-methylated-flavonoids absorb between 6.7–10.0 ppm and typically between 6.7–8.7 ppm. A comparative 13C NMR study reflects that the 13C NMR chemical shifts reported for 6-hydroxy-5-methyl-3′,4′,5′-trimethoxyaurone-4-O-α-L-rhamnoside from Pterocarpus santalinus and 8-C-methyl-5,7,2′,4′- tetramethoxyflavanone from Terminalia alata are inconsistent with the assigned structures, and therefore need reconsideration.

scholarly journals 17O and 33S Fourier Transform NMR Studies in Thiosulfate and Thiomolybdate Solutions

1976 ◽  
Vol 31 (8) ◽  
pp. 978-980 ◽  
Author(s):  
O. Lutz ◽  
W. Nepple ◽  
A. Nolle
Keyword(s):  
Fourier Transform ◽  
Chemical Shifts ◽  
Nmr Studies ◽  
Experimental Parameters

AbstractFourier Transform NMR measurements of 17O and 33S are reported for several aqueous sulfate, thiosulfate, molybdate and thinftnolybdate solutions. Using informations from 17O signals, 33S NMR lines are assigned. Experimental parameters, chemical shifts and linewidths are given.

9Be nuclear magnetic resonance spectroscopy trends in discrete complexes: an update

2020 ◽  
Vol 75 (5) ◽  
pp. 459-472 ◽  
Author(s):  
Jenna K. Buchanan ◽  
Paul G. Plieger
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Solution Nmr ◽  
Resonance Spectroscopy ◽  
Coordination Numbers ◽  
Solution Nmr Spectroscopy ◽  
Beryllium Complexes

Abstract9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the 9Be NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of four-coordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller ω1/2 values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF C-HEXYL CALIX[4]RESORCINARENA FROM RESORCINOL-HEPTANAL CONDENSATION

2016 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Desi Suci Handayani ◽  
Zainal Arifin Almaqqomul Amin ◽  
Triana Kusumaningsih ◽  
Abu Masykur
Keyword(s):  
Melting Point ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Chemical Shifts ◽  
Condensation Reaction ◽  
Wave Number ◽  
Synthesis And Characterization ◽  
H Nmr ◽  
Brown Powder

<p>Synthesis of  C-hexyl  calix[4]resorcinarene  through condensation reaction between resorcinol  and  heptanal  with  HCl  catalyst  has  been  investigated.  Synthesis  conducted  by the ratio of resorcinol: heptanal (1:1) using reflux for 6 hours in ethanol. Structural  analysis of  the  product  was  done  by  FTIR  and 1 H-NMR  spectroscopy,  while  the  characterization was  done  by  determining  melting  point.  The  product  was  golden  brown  powder  with  a yield 99.43%  and  melting point more than 300 °C.  Structural analysis with FTIR and 1 HNMR  known  vibration  and  signals  characteristic  of  calix[4]resorcinarena  group, the vibrations of the CH  bridge. Vibration of CH bridge appearance at wave number 1445 cm<sup>-1</sup> and 1456  cm<sup>-1</sup>, while signal of CH bridge appearance at chemical shifts from  4.17 to 4.21 ppm.</p>

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