A Proton Magnetic Resonance Study of the Effect of 2′-O-Methylation on Ribonucleoside Conformation

1973 ◽  
Vol 51 (7) ◽  
pp. 1099-1106 ◽  
Author(s):  
Frank E. Hruska ◽  
Alan Mak ◽  
Harwant Singh ◽  
David Shugar
Keyword(s):  
Proton Magnetic Resonance ◽  
Molecular Conformation ◽  
Chemical Shifts ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Dimensional Structure ◽  
Aqueous Environment ◽  
Magnetic Resonance Study ◽  
Proton Magnetic Resonance Study ◽  
Methyl Derivatives

The 100- and 220- MHz p.m.r. spectra of uridine, cytidine, and their 2′-O-methyl derivatives are obtained in aqueous solution at several temperatures. The experimental chemical shifts and coupling constants are discussed in terms of the overall molecular conformation. The conclusion is reached that 2′-O-methylation has little effect upon the three-dimensional structure of a nucleoside at the monomer level in an aqueous environment.

A Proton Magnetic Resonance Study of the Ultraviolet Photoproduct of d(TpT) in Aqueous Solution

1975 ◽  
Vol 53 (8) ◽  
pp. 1193-1203 ◽  
Author(s):  
Frank E. Hruska ◽  
Donald J. Wood ◽  
Kelvin K. Ogilvie ◽  
James L. Charlton
Keyword(s):  
Aqueous Solution ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Magnetic Resonance Study ◽  
Parent Molecule ◽  
Terminal Fragment ◽  
Proton Magnetic Resonance Study ◽  
Cyclobutane Ring

The p.m.r. data of d(TpT) and its predominant u.v. photoproduct d(T[p]T) in aqueous solution are compared. The data are consistent with the presence of a cis-syn cyclobutane ring in d(T[p]T). Consideration of the H1′ chemical shifts leads to the conclusion that changes in the sugar–base torsion angle of both nucleotide fragments of the parent molecule are required to bring the thymine bases into alignment for photodimerization. The coupling constants indicate that the conformation of the 5′-terminal fragment is only slightly affected by the cyclobutane ring formation. Photodimerization brings about a distortion of the sugar pucker in the 3′-terminal fragment. In this fragment both the gauche-gauche and gauche-trans conformers are significantly populated whereas the trans-gauche form is excluded.

A Comparative Proton Magnetic Resonance Study of the Molecular Conformation of Uracil and 6-Aza Uracil Nucleosides and Nucleotides

1973 ◽  
Vol 51 (15) ◽  
pp. 2571-2577 ◽  
Author(s):  
Donald J. Wood ◽  
Frank E. Hruska ◽  
Richard J. Mynott ◽  
Ramaswamy H. Sarma
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Molecular Conformation ◽  
Three Dimensional ◽  
Magnetic Resonance Study ◽  
Magnetic Resonance Data ◽  
Ribose Phosphate ◽  
Resonance Data ◽  
Proton Magnetic Resonance Study ◽  
Proton Magnetic Resonance Data

Proton magnetic resonance data for uridine and uridine-5′-monophosphate, and the corresponding 6-azauracil analogs, are presented and discussed in terms of their overall three dimensional conformations in aqueous solution. The data reveal a destabilizing influence of the 6-aza base upon the gog and g′–g′ conformation of the ribose phosphate moiety.

A PROTON MAGNETIC RESONANCE STUDY OF N-BIS(2-HALOETHYL)AMINES

1965 ◽  
Vol 43 (6) ◽  
pp. 1792-1797 ◽  
Author(s):  
George R. Pettit ◽  
Joseph A. Settepani ◽  
Ralph A. Hill
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Nitrogen Mustard ◽  
Chemical Shifts ◽  
Deuterium Oxide ◽  
The Self ◽  
Magnetic Resonance Study ◽  
Complex Series ◽  
Condensation Reactions ◽  
Proton Magnetic Resonance Study

The proton magnetic resonance chemical shifts of N-bis(2-haloethyl)amine hydrohalide salts have been found useful for rapidly assessing organohalide composition. An important illustration of nitogen mustard reactivity was obtained by observing the p.m.r. response of N-bis(2-haloethyl)amine hydrohalide salts (in deuterium oxide) following neutralization. In general, the amines rapidly entered a complex series of intra- and inter-molecular reactions. Among the substances studied N-bis(2-fluoroethyl)amine was by far the most stable and remained essentially unchanged during a 7-day period. By contrast N-bis(2-iodoethyl)amine was completely transformed in less than 6 min. The self-condensation reactions of, for example, N-bis(2-chloroethyl)amine appear to be accompanied by transient formation of N-2-chloroethylaziridine (IIIb). The present investigation indicates that p.m.r. spectroscopy is a valuable technique for evaluating the course of nitrogen mustard self-condensation reactions.

Proton magnetic resonance spectra of indolizine and its methyl derivatives and aza analogues

1964 ◽  
Vol 17 (10) ◽  
pp. 1128 ◽  
Author(s):  
PJ Black ◽  
ML Heffernan ◽  
LM Jackman ◽  
QN Porter ◽  
GR Underwood
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Iterative Procedure ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Methyl Derivatives ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of indolizine, indolizine-1,3-d2, 1- and 2-methylindolizine, 2,3-, 2,5-, 2,6-, and 2,7-dimethylindolizine and 1-, 2-, and 3-azaindolizine have been determined at 100 and/or 60 Mc/s. Unequivocal assignments have been made to all protons and the coupling constants and chemical shifts for indolizine and its aza analogues have been obtained by an iterative procedure. Long-range coupling constants involving protons separated by five and six bonds have been observed.

Determination of the molecular conformation of uridine in aqueous solution by proton magnetic resonance spectroscopy. Comparison with β-pseudouridine

1970 ◽  
Vol 48 (18) ◽  
pp. 2866-2870 ◽  
Author(s):  
Barry J. Blackburn ◽  
Arthur A. Grey ◽  
Ian C. P. Smith ◽  
Frank E. Hruska
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Molecular Conformation ◽  
Chemical Shifts ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Resonance Spectroscopy ◽  
Proton Coupling ◽  
Anti Conformation

A complete analysis of the 220 MHz proton magnetic resonance spectrum of aqueous uridine is reported. From the data a model for the molecular conformation is presented and compared with that of β-pseudouridine. It is concluded that in both compounds the ribose rings are in rapid equilibrium between classical puckered structures. The temperature-independence of the ribose proton coupling constants and chemical shifts suggests that all the conformers involved in this equilibrium have very similar energies. Both compounds exhibit a preference for the gauche–gauche rotamer about the exocyclic 4′—5′ bond; this conclusion is shown to be independent of the parameters in the Karplus equation or the energy minima chosen for the rotamers. The anti conformation of the uracil base is shown to exist in both compounds. It is proposed that the special structural significance of β-pseudouridine in transfer RNA must be due to the potential hydrogen bond that may be formed by the nitrogen atom at position one in uracil.

Proton magnetic resonance study of conformational dynamics, coordinated internal motions, and chemical shifts of tocinamide

Biochemistry ◽  
1977 ◽  
Vol 16 (10) ◽  
pp. 2248-2254 ◽  
Author(s):  
Leslie J. F. Nicholls ◽  
Claude R. Jones ◽  
William A. Gibbons
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Conformational Dynamics ◽  
Magnetic Resonance Study ◽  
Internal Motions ◽  
Proton Magnetic Resonance Study
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