One dimensional nuclear Overhauser effect with two dimensional heteronuclear multiple quantum coherence detection: proton-proton nitrogen-15 correlation in T4 lysozyme

1988 ◽  
Vol 110 (20) ◽  
pp. 6885-6886 ◽  
Author(s):  
David F. Lowry ◽  
Alfred G. Redfield ◽  
Lawrence P. McIntosh ◽  
Frederick W. Dahlquist

Biochemistry ◽  
1986 ◽  
Vol 25 (12) ◽  
pp. 3659-3665 ◽  
Author(s):  
Mukti H. Sarma ◽  
Goutam Gupta ◽  
Ramaswamy H. Sarma


Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 409 ◽  
Author(s):  
Chi Ding ◽  
Ji Ong ◽  
Hui Goh ◽  
Cynthia Coffill ◽  
Lik Tan

Benderamide A (1), a (S)-2,2-dimethyl-3-hydroxy-7-octynoic acid (S-Dhoya)-containing cyclic depsipeptide that belongs to the kulolide superfamily, was isolated from a Singapore collection of cf. Lyngbya sp. marine cyanobacterium using a bioassay-guided approach. While the planar structure of 1 was elucidated using a combination of 1D and 2D NMR experiments and MS analysis, the absolute configuration was subsequently achieved using the results obtained from Marfey’s analysis, comparative analysis of nuclear overhauser effect spectroscopy (NOESY) with the known compound 3, and one dimensional-nuclear overhauser effect (1D-NOE). Although 1 did not display antiproliferative activity against MCF7 breast cancer cells, the presence of an Ala instead of Gly suggests a possible mechanistic pathway to explain the consequential decrease in cytotoxicity compared to the closely related 2. In addition, results obtained from an LC–MS/MS-based molecular networking algorithm revealed two other closely related compounds encouraging further identification and isolation from the same marine cyanobacterium extract.



1995 ◽  
Vol 28 (4) ◽  
pp. 641-650
Author(s):  
Weiping Shao ◽  
Xiaoling Huang ◽  
Gaohua Liu ◽  
Houming Wu ◽  
Wenxia Tang


1983 ◽  
Vol 36 (11) ◽  
pp. 2227 ◽  
Author(s):  
GR Smith ◽  
B Ternai

By considering the technique involving the measurement of aromatic solvent-induced shifts, and the models which have been proposed from the results of such measurements, it is suggested that the use of the solvent-induced solute proton intermolecular relaxation rate [(1/T1)solvinter] is a better method to study local solvation of solute molecules. Proton relaxation rates obtained for simple solutes in the solvent benzene are analysed in terms of an interaction parameter I, which treats (1/T1)solvinter] in terms of a proton-proton pair distribution function. The resultant dependence between I and a calculated measure of the local polarity of the observed solute is discussed in terms of previously proposed models of solute-solvent interactions.



ChemPhysChem ◽  
2014 ◽  
Vol 15 (9) ◽  
pp. 1872-1879 ◽  
Author(s):  
Bharathwaj Sathyamoorthy ◽  
David M. Parish ◽  
Gaetano T. Montelione ◽  
Rong Xiao ◽  
Thomas Szyperski


1995 ◽  
Vol 311 (2) ◽  
pp. 681-688 ◽  
Author(s):  
K Kanamori ◽  
B D Ross ◽  
E L Kuo

The dependence of the in vivo rate of glutamine synthesis on the substrate ammonia concentration was studied in rat brain by 1H-15N heteronuclear multiple-quantum coherence-transfer NMR in combination with biochemical techniques. In vivo rates were measured at various steady-state blood and brain ammonia concentrations within the ranges 0.4-0.55 mumol/g and 0.86-0.98 mumol/g respectively, after low-rate intravenous 15NH4+ infusion (isotope chase). The rate of glutamine synthesis at steady state was determined from the change in brain [5-15N]glutamine levels during isotope chase, observed selectively through the amide proton by NMR, and 15N enrichments of brain glutamine and of blood and brain ammonia measured byN gas chromatography-MS. The in vivo rate (v) was 3.3-4.5 mumol/h per g of brain at blood ammonia concentrations (s) of 0.40-0.55 mumol/g. A linear increase of 1/v with 1/s permitted estimation of the in vivo glutamine synthetase (GS) activity at a physiological blood ammonia concentration to be 0.4-2.1 mumol/h per g. The observed ammonia-dependence strongly suggests that, under physiological conditions, in vivo GS activity is kinetically limited by sub-optimal in situ concentrations of ammonia as well as glutamate and ATP. Comparison of the observed in vivo GS activity with the reported in vivo rates of glutaminase and of gamma-aminobutyrate (GABA) synthesis suggests that, under mildly hyperammonaemic conditions, glutamine is synthesized at a sufficiently high rate to serve as a precursor of GABA, but glutaminase-catalysed hydrolysis of glutamine is too slow to be the sole provider of glutamate used for GABA synthesis.



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