(13C)-Substituted erythronucleosides: synthesis and conformational analysis by proton and carbon-13 NMR spectroscopy
摘要:
The erythronucleosides, 9-beta-D-erythrofuranosyladenine (1b), 1-beta-D-erythrofuranosylcytosine (2b), 9-beta-D-erythrofuranosylguanine (3b), and 1-beta-D-erythrofuranosyluracil (4b), were synthesized with and without C-13-substitution at C1' of the furanose ring. 75-MHz C-13 and 620-MHz H-1 NMR spectra of 1-4b were interpreted, in the latter case with the assistance of spectral simulation, and H-1-H-1, C-13-H-1, and C-13-C-13 spin couplings were used to assess furanose conformation. 3J(HH) data in (H2O)-H-2 were treated by computer to determine the preferred north and south conformers, their puckering amplitudes, and their mole fractions in solution, and J(CH) data were used to complement this analysis. A similar treatment of spin coupling data for the corresponding ribonucleosides 1-4a was also conducted to permit a comparison of furanose conformations in both series of compounds. Results show that the removal of the exocyclic hydroxymethyl group from 1-4a, giving 1-4b, significantly enhances the proportion of south conformers in aqueous ((H2O)-H-2) solution.
Biomimetic Simulation of Free Radical-Initiated Cascade Reactions Postulated To Occur at the Active Site of Ribonucleotide Reductases<sup>1</sup>
作者:Morris J. Robins、Zhiqiang Guo、Mirna C. Samano、Stanislaw F. Wnuk
DOI:10.1021/ja983449p
日期:1999.2.1
erythrofuranosyl nucleosides. Analogous treatment of 6‘-O-nitro esters of homonucleosides [(5-deoxy-β-d-ribo-hexofuranosyl)adenine or uracil nucleosides derivedfrom d-glucose] resulted in generation of a 6‘-oxygen radical followed by abstraction of H3‘ by a [1,5]-hydrogen shift. Radical quenching with tributyltin deuteride gave 3‘-[2H]homonucleosides. This deuterium transfer, and inversion of configuration at C3‘
[EN] SYNTHETIC ANTIGENS FOR TUBERCULOSIS DETECTION<br/>[FR] ANTIGÈNES SYNTHÉTIQUES POUR LA DÉTECTION DE LA TUBERCULOSE
申请人:KEI INTERNATIONAL LTD
公开号:WO2020030034A1
公开(公告)日:2020-02-13
Provided herein are a synthetic antigen and a solid substrate comprising an antigen immobilized thereto and a method for immobilizing said antigen onto a solid substrate. Provided herein are also a biosensor and tuberculosis detection system comprising said solid substrate. Provided herein is also a method of detecting the presence of antibodies against mycobacterial material in a sample using said synthetic antigen or solid substrate.