Synthesis and `double click' density functionalization of 8-aza-7-deazaguanine DNA bearing branched side chains with terminal triple bonds

Autor(en): Seela, Frank
Xiong, Hai
Budow, Simone
Stichwörter: ALKYNE; Chemistry; Chemistry, Organic; Click reaction; CONJUGATION; Cycloaddition; DELIVERY; DERIVATIVES; DNA; Modified bases; MOLECULAR RECOGNITION; NUCLEOLIPIDS; NUCLEOSIDES; OLIGONUCLEOTIDES; PCR; Pyrazolo[3,4-d]pyrimidine
Erscheinungsdatum: 2010
Volumen: 66
Ausgabe: 22
Startseite: 3930
Seitenende: 3943
The 7-[di(prop-2-ynl)amino]prop-1-ynyl derivative of 8-aza-7-deaza-2'-deoxyguanosine (1) was synthesized from 7-iodo-8-aza-7-deaza-2'-deoxyguanosine (7) by Sonogashira cross-coupling and converted into the phosphoramidite building block 10. Oligonucleotides bearing branched side chains with terminal triple bonds were prepared by solid-phase synthesis containing single or multiple residues of 1 as 2'-deoxyguanosine surrogates. Tin measurements demonstrate that compound 1 has a positive effect on duplex stability, which is comparable to the stabilizing effect of the octa-1,7-diynylated non-branched nucleoside 2. Nucleoside 1 and corresponding oligonucleotides were functionalized by the Cu(I)-mediated 1,3-dipolar cycloaddition `double click' reaction with diverse ligands (AZT 3, benzyl azide 4,11-azidoundecanol 5 and m-dPEG(4)(TM)-azide 6). The conjugation reactions were carried out in solution and on solid support. Nucleoside 1 allowed `double' functionalization of a single residue with two reporter groups. The `double click' reaction proceeded smoothly even when two residues of nucleoside 1 were arranged in proximal positions. Hybridization with complementary strands led to a stable oligonucleotide duplex. Molecular modeling indicates that inspite of the crowded steric situation with four AZT ligands within closest proximal positions, all ligands are well accommodated in the major groove not disturbing the DNA helix. (C) 2010 Elsevier Ltd. All rights reserved.
ISSN: 00404020
DOI: 10.1016/j.tet.2010.03.086

Show full item record

Page view(s)

Last Week
Last month
checked on Feb 20, 2024

Google ScholarTM