In nucleoside/nucleotide chemistry, the regioselective cleavage of 5′-O-TBS groups of persilylated nucleosides is a desired approach for structural functionalization at the 5′-position. However, efficient and practical methods for this purpose are still limited. In our research, we found that homogeneous methanolic phosphomolybdic acid (PMA) efficiently catalyzes the regioselective deprotection of
Synthesis and Conformational Analyses of Cyclonucleoside Having 13-Membered Ring Bridging Nucleobase and 5′-Position via a Linker Containing Sulfonamide
intermediate that contained both a sulfonyltriazole and amino groups. Both 1H NMR and computational studies revealed that the sugarconformation, base orientation, and γ torsion angle were S-type, anti, and trans, respectively. As such, cyclic nucleosides show promise for introducing these specific distorted conformations into functional nucleic acids.
Design and Synthesis of 3‘- and 5‘-<i>O</i>-(3-Benzenesulfonylfuroxan-4-yl)-2‘-deoxyuridines: Biological Evaluation as Hybrid Nitric Oxide Donor−Nucleoside Anticancer Agents
作者:Sameh Moharram、Aihua Zhou、Leonard I. Wiebe、Edward E. Knaus
DOI:10.1021/jm030544m
日期:2004.3.1
A group of 3'-O- and 5'-O-(3-benzenesulfonylfuroxan-4-yl)-2'-deoxyuridines possessing a variety of substituents (H, Me, 1, F, CF3) at the C-5 position of the nucleoside moiety were synthesized for evaluation as hybrid anticancer agents that have the ability to simultaneously release cytotoxic nitric oxide ((NO)-N-.). Incubation of these nitric oxide donor-nucleoside conjugates in the presence of 18 MM L-cysteine released a high percentage of (NO)-N-. (21-48% at 1 h; 37-86% at 16 h). The release of (NO)-N-. in the absence of the thiol cofactor was negligible. These hybrid (NO)-N-. donor-nucleosides exhibited high cellular toxicity (CC50 = 10(-6)-10(-8) M range) against a battery of tumor cell lines (143B-LTK, 14313, EMT-6, KBALB-STK, and KBALB) and normal human fibroblasts (Hs578Bst). No differences in cytotoxicity between nontransfected (143B, KBALB) and the corresponding transfected (143B-LTK, KBALB-STK) cancer cell lines possessing the herpes simplex virus type 1 (HSV-1) thymidine kinase gene (TK+) were observed, indicating that expression of the viral TK enzyme did not provide a gene therapeutic effect.