Triazolyl C-nucleosides via the intermediacy of β-1′-ethynyl-2′-deoxyribose derived from a Nicholas reaction: Synthesis, photophysical properties and interaction with BSA
| Autor: | Subhendu Sekhar Bag, Suman Kalyan Das |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Quenching (fluorescence) 010405 organic chemistry Organic Chemistry Solvatochromism Nicholas reaction Alkyne 010402 general chemistry 01 natural sciences Biochemistry Acceptor Combinatorial chemistry 0104 chemical sciences chemistry.chemical_compound Deoxyribose chemistry Intramolecular force Drug Discovery Click chemistry |
| Zdroj: | Tetrahedron. 75:3024-3037 |
| ISSN: | 0040-4020 |
| Popis: | We report the design and synthesis of triazolyl donor/acceptor unnatural C-nucleosides via alkyne (sugar)—azide (aromatic) 1, 3-dipolar cyclo-addition reaction as a key step and studies on their photophysical properties. We have chosen β-1′-ethynyl-2′-deoxyribose as a precursor to synthesize triazolyl-C-nucleosides. Overcoming the difficulties, we obtain β-1′-ethynyl-2′-deoxyribose as a major product following a Co2(CO)8 catalyzed intramolecular Nicholas reaction. The 1,3-diaxial interaction is the driving force for the α to β-anomeric conversion while performing cobalt complexation followed by oxidation to afford β-1′- ethynyl-2′-deoxyribose as the major product. A Cu(I)-catalyzed click reaction between different aromatic donor/acceptor azides and β-1′- ethynyl-2′-deoxyribose generates the desired unnatural triazolyl donor-acceptor aromatic C-nucleosides (cTBDo/Ac) within 30 min. Single crystal X-ray structure shows the puckered conformation of sugar as C3′-exo. Studies on the photophysical properties suggests good fluorophoric as well as solvatochromic characteristics of these nucleosides. Two of the synthesised nucleosides, cTAnthBDo and cTPyBDo, are found to interact with BSA as the only tested protein with quenching of fluorescence signal. The designed bases, thus, might find applications in stabilizing a DNA and in the biophysical study thereof, if a pair of such donor acceptor C-nucleosides could be incorporated into a DNA sequence. |
| Databáze: | OpenAIRE |
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