Hydrogelation and spontaneous fiber formation of 8-aza-7-deazaadenine nucleoside `click' conjugates
Autor(en): | Seela, Frank Pujari, Suresh S. Schaefer, Andreas H. |
Stichwörter: | `Click' conjugates; AZIDE; Chemistry; Chemistry, Organic; GELATION ABILITY; GELATORS; GUANOSINE; HELIX FORMATION; Hydrogelation; Modified nucleosides; ORGANOGELS; Pyrazolo[3,4-d]pyrimidines; WATER GELATION | Erscheinungsdatum: | 2011 | Herausgeber: | PERGAMON-ELSEVIER SCIENCE LTD | Journal: | TETRAHEDRON | Volumen: | 67 | Ausgabe: | 38 | Startseite: | 7418 | Seitenende: | 7425 | Zusammenfassung: | Nucleoside hydrogels based on benzyl azide `click' conjugates of 8-aza-7-deaza-2'-deoxyadenosine bearing 7-ethynyl, 7-octa-(1,7-diynyl), and 7-tri-prop-2-ynyl-amine side chains were synthesized (1, 3, 4). The cycloaddition adduct with the shortest linker (1) yields the most powerful hydrogelator forming stable gels at a concentration of 0.3 wt % of 1 in water. One molecule of 1 catches 7500 water molecules. Cycloaddition of the 8-aza-7-deaza-7-azido-2'-deoxyadenosine (9) and 3-phenyl-1-propyne (10) leads to the isomeric conjugate 2, with a C-N connectivity between the nucleobase and triazole moiety. This gel is less stable than that of the adduct 1. Both gels show a similar stability over a wide pH range (4.0-10.0). Xerogels of 1 and 2 studied by scanning electron microscopy (SEM) reveal that both click adducts (1 and 2) form long fibers spontaneously. (C) 2011 Elsevier Ltd. All rights reserved. |
ISSN: | 00404020 | DOI: | 10.1016/j.tet.2011.07.015 |
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