In contrast to tetrazole, pyridine hydrochloride/imidazole converts nucleoside phosphoramidites to intermediates that show a high preference for phosphitilating hydroxyl groups relative to nucleoside amino groups. Use of this activating agent and incorporation of a pyridine hydrochloride/aniline wash step in the synthetic cycles permit synthesis of mixed base twenty-mer oligonucleotides from nu...

DNA labeling in vivo using nucleoside analogues is a current experimental approach to determine cell proliferation rates in cell cultures and tissues. It has also been successfully used to localize adult stem cell niches through the identification of nucleoside label-retaining cells (LRC) in long-term experiments. A major hindrance of this methodology relies on the selection of adequate procedu...

The synthesis of the novel nucleotide analogues 5'-deoxynucleoside-5'-S-methylphosphonates, starting from 5'-deoxy-5'-haloribonucleosides, 5'-O-tosylribonucleosides, and 2'-O-triflylnucleosides, is described. The phosphonothiolation of these compounds was achieved using S-(diisopropylphosphonomethyl)isothiouronium tosylate, a new, odourless, and efficient equivalent of mercaptomethylphosphonate...

Nucleoside analogues are widely employed as bioactive compounds against cancer and viral infections. Consequently, it is important to develop efficient synthetic methods to access them with high efficiency and structural diversity. Herein, we present a full account of our work on the synthesis of nucleoside analogues via annulations of donor acceptor aminocyclopropanes and aminocyclobutanes. Th...

Development of probes that can discriminate G-quadruplex (GQ) structures and indentify efficient GQ binders on the basis of topology and nucleic acid type is highly desired to advance GQ-directed therapeutic strategies. In this context, we describe the development of minimally perturbing and environment-sensitive pyrimidine nucleoside analogues, based on a 5-(benzofuran-2-yl)uracil core, as top...

Novel 5'-deoxythreosyl purine phosphonic acid analogues containing a 2'-electropositive moiety such as fluorine atom, were designed and synthesized from commercially available 1,3-dihydroxy acetone. Condensation successfully proceeded from a glycosyl donor 6 under Vorbrüggen conditions and cross-metathesis gave the desired phosphonate analogues 7a, 7b, 17a and 17b. The synthesized nucleoside ph...

2'-Fluoro-2'3'-dideoxyarabinosyladenine (F-ddA), a nucleoside reverse transcriptase inhibitor of human immunodeficiency virus (HIV) replication, is currently being evaluated in clinical trials. Future monotherapy for the treatment of HIV is unlikely owing to the rapid emergence of drug-resistant viruses, so F-ddA was evaluated in combination with a variety of mechanistically diverse inhibitors ...

Several laboratories have reported studies on individual enzymes that belong to the general class of adenosine triphosphate : nucleoside monophosphate phosphotransferases (EC 2.7.4.4), commonly termed nucleoside monophosphate kinases (l-7). Studies with partially purified enzyme preparations have indicated that a variety of nucleoside monophosphates can serve as alternative substrates for nucle...

(Carbo)nucleoside derivatives constitute an important class of pharmaceuticals, yet there are only few convergent methods to access new analogues. In this communication, we report the first synthesis of thymine, uracil and 5-fluorouracil substituted diester donor-acceptor cyclopropanes and their use in the indiumand tin-catalyzed [3+2] annulations with aldehydes, ketones and enol ethers. The ob...

BACKGROUND Inosine triphosphatase (ITPase) is encoded by the polymorphic gene ITPA and maintains low intracellular levels of the inosine nucleotides ITP and dITP. The most frequently reported polymorphisms are ITPA c.94C>A (rs 1127354) and ITPA c. 124+21 A>C (rs7270101). Some nucleoside-analogues used in the treatment of HIV-seropositive (HIV+) patients are potential substrates for ITPase. Ther...