4546-72-9Relevant articles and documents
Base-base recognition of nonionic dinucleotide analogues in an apolar environment studied by low-temperature NMR spectroscopy
Xiao, Zhou,Weisz, Klaus
scheme or table, p. 3862 - 3869 (2010/05/15)
Two self-complementary dinucleotide analogues TSiA and A si with a nonionic diisopropylsilyl-modified backbone were synthesized, and their association in a nonaqueous aprotic environment was studied by NMR spectroscopy. Using a CDClF2/CDF3 solvent mixture, measurements at temperatures as low as 113 K allowed the observation and structural characterization of individual complexes in the slow exchange regime. The AsiT analogue associates to exclusively form a dinucleotide antiparallel duplex with regular Watson-Crick base pairing, but both A and T nucleosides exhibit a predominant C3'-endo sugar pucker reminiscent of an A-type conformation. In contrast to AsiT the TSiA dinucleotide is found to exhibit significant variability and flexibility. Thus, different secondary structures with weaker hydrogen bonds for all T SiA structures are observed at low temperatures. Although a B-like Watson-Crick antiparallel dinucleotide duplex with a preferred C2'-endo sugar pucker largely predominates at temperatures above 153 K, two additional species, namely a dinucleotide Hoogsteen duplex with a syn glycosidic torsion angle of the adenosine nucleoside and a presumably intramoleculariy folded structure, are increasingly populated upon further cooling. By adding typical DNA intercalators like anthracene or benz[c]acridine derivatives to the A siT dinucleotide duplex in the aprotic solvent environment, no binding of the polycyclic aromatic molecules can be detected even at lower temperatures. Obviously, van der Waals and stacking interactions are insufficient to compensate for the other unfavorable contributions to the overall free energy of binding, and only in the presence of additional hydrophobic effects in an aqueous environment does binding occur.
An enzymatic transglycosylation of purine bases
Roivainen, Jarkko,Elizarova, Tatiana,Lapinjoki, Seppo,Mikhailopulo, Igor A.,Esipov, Roman S.,Miroshnikov, Anatoly I.
, p. 905 - 909 (2008/09/17)
An enzymatic transglycosylation of purine heterocyclic bases employing readily available natural nucleosides or sugar-modified nucleosides as donors of the pentofuranose fragment and recombinant nucleoside phosphorylases as biocatalysts has been investigated. An efficient enzymatic method is suggested for the synthesis of purine nucleosides containing diverse substituents at the C6 and C2 carbon atoms. The glycosylation of N6-benzoyladenine and N2-acetylguanine and its O6-derivatives is not accompanied by deacylation of bases. Copyright Taylor & Francis Group, LLC.
An improved transient method for the synthesis of N-benzoylated nucleosides
Zhu, Xue-Feng,Williams Jr., Howard J.,Scott, A. Ian
, p. 1233 - 1243 (2007/10/03)
The Jones' transient method for the synthesis of N-benzoylated nucleosides is improved by reducing the amounts of chlorotrimethylsilane (TMSCl) and benzoyl chloride to nearly equivalent quantities. The easy work-up and high yields of products are the major advantages of this approach. Jones' method is further simplified by omitting the addition of ammonium hydroxide. The utility of this modification for the preparation of some useful protected nucleosides is also presented.
