161002-01-3Relevant academic research and scientific papers
Synthesis of purine and 7-deazapurine nucleoside analogues of 6-N-(4-nitrobenzyl)adenosine; Inhibition of nucleoside transport and proliferation of cancer cells
Rayala, Ramanjaneyulu,Theard, Patricia,Ortiz, Heysell,Yao, Sylvia,Young, James D.,Balzarini, Jan,Robins, Morris J.,Wnuk, Stanislaw F.
, p. 2186 - 2192 (2014)
Human equilibrative nucleoside transporter 1 (hENT1) is a prototypical nucleoside transporter protein ubiquitously expressed on the cell surface of almost all human tissue. Given the role of hENT1 in the transport of nucleoside drugs, an important class of therapeutics in the treatment of various cancers and viral infections, efforts have been made to better understand the mechanisms by which hENT1 modulates nucleoside transport. To that end, we report here the design and synthesis of novel tool compounds for the further study of hENT1. The 7-deazapurine nucleoside antibiotic tubercidin was converted into its 4-N-benzyl and 4-N-(4-nitrobenzyl) derivatives by alkylation at N3 followed by a Dimroth rearrangement to the 4-N-isomer or by fluoro-diazotization followed by SNAr displacement of the 4-fluoro group by a benzylamine. The 4-N-(4-nitrobenzyl) derivatives of sangivamycin and toyocamycin antibiotics were prepared by the alkylation approach. Cross-membrane transport of labeled uridine by hENT1 was inhibited to a weaker extent by the 4-nitrobenzylated tubercidin and sangivamycin analogues than was observed with 6-N-(4-nitrobenzyl)adenosine. Type-specific inhibition of cancer cell proliferation was observed at micromolar concentrations with the 4-N-(4-nitrobenzyl) derivatives of sangivamycin and toyocamycin, and also with 4-N-benzyltubercidin. Treatment of 2′,3′,5′-O-acetyladenosine with aryl isocyanates gave the 6-ureido derivatives but none of them exhibited inhibitory activity against cancer cell proliferation or hENT1.
Nucleosides. Part LVI. Aminolysis of carbamates of adenosine and cytidine
Sigmund,Pfleiderer
, p. 1267 - 1280 (2007/10/02)
The 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) group, introduced 1984 as protecting group for exocyclic amino functions of nucleic-acid bases, reacts with amines under mild conditions to urea derivatives. Treatment of 2',5'-di-O-acetyl-N6-[2-(4-nitrophenyl)ethoxycarbonyl]cordycepin (3) with NH3/MeOH overnight at room temperature affords cordycepin (4) and N6-carbamoylcordycepin (5). Preliminary investigations towards the elucidation of the reaction mechanism indicate that the aminolysis proceeds via an addition-elimination or an isocyanate mechanism, depending on the reaction conditions. The phenoxycarbonyl (phoc) group at N6 or N4 was chosen to study the mild conversion of carbamates with aromatic amines into ureas of adenosine and cytidine, respectively.
