Nuclear magnetic resonance studies of nucleoside- and nucleotide-metal interactions. 2. Carbon-13 nuclear magnetic resonance study of binding of manganese(II) to purine and pyrimidine nucleosides and nucleotides

Biochemistry ◽  
1973 ◽  
Vol 12 (18) ◽  
pp. 3434-3439 ◽  
Author(s):  
George Kotowycz ◽  
Osamu Suzuki



1965 ◽  
Vol 18 (9) ◽  
pp. 1405 ◽  
Author(s):  
IRC Bick ◽  
DHS Horn

From a nuclear magnetic resonance study of the tautomerism of tasmanone and 1,1,3,3-tetramethylphloroglucinol (syncarpic acid), it is deduced that tasmanone consists of a mixture of tautomers (I) and (II) with the tautomer (I) present in the larger proportion. Similarly it is deduced that the tautomers of agglomerone (XI; R = CHMe2), 3-acetyl-O-methylfilicinic acid (XI R; = Me), ceroptene (XI; R = CH=CHPh), and usnic acid (XIII) with the extended conjugation are the more stable and populated ones.



1974 ◽  
Vol 52 (6) ◽  
pp. 924-929 ◽  
Author(s):  
George Kotowycz

The influence of paramagnetic Cu2+ ions on the proton decoupled 13C n.m.r. spectra of pyrimidine nucleosides and nucleotides has been studied. For 5′-CMP, the C5 resonance is broadened first on the addition of Cu2+ ions followed by the C2, C4, and C1′ resonances. From a comparison of the transverse and longitudinal relaxation rates of the base carbon nuclei due to the presence of Cu2+ ions, binding of Cu2+ to the N3 nitrogen of 5′-CMP is predicted. A similar broadening behavior is observed for 5′-UMP, 5′-TMP, cytidine, and uridine. This indicates that the Cu2+ ion is located near the N3 nitrogen in these Cu2+-nucleoside and -nucleotide complexes.



1977 ◽  
Vol 55 (3) ◽  
pp. 447-453 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers ◽  
C. T. Tan

The bicyclo[2.2.2]octan-2-one and -[3.2.1]octan-6-one skeletons are interconvertible under strongly basic conditions. Their α,α-dimethyl derivatives in tert-Buo−/tert-BuOH at 185 °C undergo very slow interconversion by β-proton abstraction. Using 2H nmr the stereoselectivity of deuterium incorporation at the β-methylene sites was established. The relative reactivities of β-methyl exchange in the [3.2.1] system were also determined. As models for this process, exchange in the α,α,α′,α′-tetramethyl derivatives of the monocyclic ketones, C5–C8, was also studied.



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