Synthesis and DNA incorporation of an ethynyl-bridged cytosine C-nucleoside as guanosine surrogate.
As a guanosine mimic that lacks the preference for syn or anti conformation a cytosine C-nucleoside was synthesized connecting the nucleobase at the anomeric center by an ethynyl linker. The key step was a Sonogashira cross coupling of 5-iodocytosine with 1'-ethynyl-2'-deoxyribose. The new C-nucleoside incorporated into G/C-alternating oligonucleotides emerged as guanosine substitute, however, with reduced duplex stability. B-Form DNA was strongly stabilized by the new surrogate even in typically Z-DNA forming sequences and in Z-form inducing environment.
Heinrich
Daniel
D
Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany.
Wagner
Thomas
T
Diederichsen
Ulf
U
D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003596:Cytosine / Q000737:chemistry*; D004247:DNA / Q000138:chemical synthesis* / Q000737:chemistry; D006151:Guanosine / Q000737:chemistry*; D015394:Molecular Structure; D044366:Transition Temperature
D003432:Cross-Linking Reagents; D006151:Guanosine; D003596:Cytosine; D004247:DNA