Direct Bromination of a Nucleotide

Ashley Swiggett

Advisor: Dr. Prigodich

            A modified nucleotide is brominated as an intermediate toward creating an double-stranded oligonucleotides with single 3'-phosphonate linkages at varying points in the sequence. A 5'-protected nucleoside is reacted with thionyl bromide and pyridine in methylene chloride at -75C and allowed to warm up to room temperature. This oglionucleotide will be used to study the nature of the interactions of metal ions with the ribose-phosphate DNA backbone. Phosphorus 31 NMR will be used to measure the chemical shift and coupling constant of a single phosphonate in the oligonucleotide.  Changes in these NMR parameters will reflect the strength of binding and whether metal ions are coordinating in an inner- or outer-sphere fashion.