Proton magnetic resonance studies on short duplexes. II. The self-complementary oligoribonucleotide CpApUpG

1978 ◽  
Vol 56 (17) ◽  
pp. 2249-2252 ◽  
Author(s):  
Paul J. Romaniuk ◽  
Thomas Neilson ◽  
Donald W. Hughes ◽  
Russell A. Bell
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Double Helix ◽  
The Self ◽  
Proton Nuclear Magnetic Resonance ◽  
Base Pairs ◽  
Temperature Range ◽  
Helix Formation ◽  
Nmr Study

Proton nuclear magnetic resonance was used to examine double helix formation in the self-complementary oligoribonucleotide CAUG in neutral D2O containing 1.0 M NaCl. Using the procedure of incremental assignment all the nonexchangeable base and ribose anomeric protons could be assigned and were observed over the temperature range of 70 to 4 °C. The chemical shift changes that occurred over this temperature range were sigmoidal in nature which is indicative of base-pairing. From the plot of chemical shift vs. temperature a Tm of 24 ± 1 °C was determined. This is the first nmr study of a duplex formed from tetranucleotides which contains two internal A•U base pairs.

Proton magnetic resonance studies on short duplexes. I. Helix formation by the duplex set GpApGpC:GpCpUpC

1978 ◽  
Vol 56 (17) ◽  
pp. 2243-2248 ◽  
Author(s):  
Donald W. Hughes ◽  
Russell A. Bell ◽  
Thomas E. England ◽  
Thomas Neilson
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Neck Region ◽  
Trna Synthetase ◽  
Optical Methods ◽  
Aminoacyl Trna Synthetase ◽  
Double Stranded Rna ◽  
Magnetic Resonance Studies ◽  
Helix Formation

Proton magnetic resonance bas been used to investigate the double stranded RNA helix GAGC:GCUC, whose sequence corresponds to the duplex neck region of several tRNAs, a possible aminoacyl-tRNA synthetase recognition site. The nonexchangeable base and ribose anomeric resonances of the separate tetranucleotides were characterized by linear and predominantly upfield chemical shift changes as the temperature was decreased from 65 to 15 °C. When these strands were mixed nonlinear, sigmoidal shift changes consistent with base pairing were observed. The melting temperature of the duplex was determined to be 42 ± 1 °C which was in excellent agreement with the value obtained from optical methods. This is the first 1Hmr study of a non-self-complementary duplex prepared from synthetic tetraribonucleotides.

A STUDY OF TAUTOMERISM IN CYCLIC β-DIKETONES BY PROTON MAGNETIC RESONANCE

1965 ◽  
Vol 43 (11) ◽  
pp. 3057-3062 ◽  
Author(s):  
Natsuko Cyr ◽  
Leonard W. Reeves
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Enthalpy Change ◽  
Enol Form ◽  
Proton Resonance ◽  
Kcal Mole ◽  
Intensity Measurements ◽  
Acetonitrile Solutions ◽  
Monomer Form

The keto–enol equilibrium of cyclohexane-1,3-dione in chloroform is best interpreted from proton resonance measurements as[Formula: see text]K1 and K2 may be separately determined from chemical shift measurements of the enol-OH proton and intensity measurements of peaks assigned to keto and enol forms. K1 and K2 are satisfactorily independent of concentrations except in very dilute solutions where intensity measurements become unreliable. The overall equilibrium constant K = K1 × K22 can be obtained for the same molecule in acetonitrile solutions where the enol monomer form is in very low concentration. 5,5′-Dimethylcyclohexane-1,3-dione in chloroform has less enol form than the unsubstituted molecule. The enthalpy change associated with 'K' for cyclohexane-1,3-dione in chloroform is 2.05 ± 0.5 kcal mole−1.

scholarly journals Lithium-tetrahydroaluminat in Ether: eine NMR-Untersuchung / Lithiumtetrahydroaluminate in Ether: an NMR Study

1980 ◽  
Vol 35 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Heinrich Nöth
Keyword(s):  
Fine Structure ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Line Width ◽  
Ion Pair ◽  
Minimum Value ◽  
Ion Formation ◽  
Nmr Study ◽  
Low Concentrations

Abstract Ether solutions of LiAlH4 have been investigated by 27Al and 7Li magnetic resonance in the concentration range 3.75-0.0075 M. The Al-signal shows a fine structure due to Al-H coupling only at concentrations below 0.15 M. The observed chemical shift 27Al is only slightly concentration dependent. The line width of the 27Al signal, which is inversely proportional to T2*, reaches a minimum value at a concentration where the best resolution of the 27Al quintet is observed. This, however, is not matched by the 7Li line width whose minimum value was found at a somewhat higher concentration. The results are consistent with multiple ion formation at the higher concentrations and with an ion pair at low concentrations.

scholarly journals ORYX-MRSI: A Fully-Automated Open-Source Software for Three-Dimensional Proton Magnetic Resonance Spectroscopic Imaging Data Analysis

2021 ◽  
Author(s):  
Sevim Cengiz ◽  
Muhammed Yildirim ◽  
Abdullah Bas ◽  
Esin Ozturk-Isik
Keyword(s):  
Data Analysis ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Open Source ◽  
Proton Magnetic Resonance ◽  
Spectroscopic Imaging ◽  
Brain Atlas ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Spectral Quality ◽  
Chemical Shift Artifact

Proton magnetic resonance spectroscopic imaging (1H-MRSI) provides noninvasive evaluation of brain metabolism. However, there are some limitations of 1H-MRSI preventing its wider use in the clinics, including the spectral quality issues, partial volume effect and chemical shift artifact. Additionally, it is necessary to create metabolite maps for analyzing spectral data along with other MRI modalities. In this study, a MATLAB-based open-source data analysis software for 3D 1H-MRSI, called Oryx-MRSI, which includes modules for visualization of raw 1H-MRSI data and LCModel outputs, chemical shift correction, tissue fraction calculation, metabolite map production, and registration onto standard MNI152 brain atlas while providing automatic spectral quality control, is presented. Oryx-MRSI implements region of interest analysis at brain parcellations defined on MNI152 brain atlas. All generated metabolite maps are stored in NIfTI format. Oryx-MRSI is publicly available at https://github.com/sevimcengiz/Oryx-MRSI along with six example datasets.

Proton Magnetic Resonance Chemical Shift Imaging ( 1 H CSI)-Directed Stereotactic Biopsy

2001 ◽  
Vol 143 (1) ◽  
pp. 45-50 ◽  
Author(s):  
B.-C. Son ◽  
M.-C. Kim ◽  
B.-G. Choi ◽  
E.-N. Kim ◽  
H.-M. Baik ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Stereotactic Biopsy ◽  
Chemical Shift Imaging

Proton Magnetic Resonance Spectra of Some Substituted 2-Acylamino-3-arylamino-1,4-naphthoquinones

1976 ◽  
Vol 31 (2) ◽  
pp. 261-263 ◽  
Author(s):  
N. L. Agarwal ◽  
R. L. Mttal
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Substitution Pattern ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of a number of substituted 2-acylamino-3-arylamino-1,4-naphthoquinones have been measured and discussed. The effect of various substitution pattern and hetero atoms on the chemical shift values of N-acylmethyl protons have been studied and explained.

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