Synthesis and crystallographic analysis of 5-Se-thymidine DNAs.
Hassan, A.E., Sheng, J., Jiang, J., Zhang, W., Huang, Z.(2009) Org Lett 11: 2503-2506
- PubMed: 19469515 
- DOI: https://doi.org/10.1021/ol9004867
- Primary Citation of Related Structures:  
3BM0 - PubMed Abstract: 
We investigated the possibility of the interaction of 5-CH(3) of thymidine and its 5'-phosphate backbone (C-H...O(-)-PO(3) interaction) in DNA via the insertion of the atomic probe (a selenium atom) into the exo-5-position of thymidine (5-Se-T). 5-Se-T was synthesized for the first time, via Mn(OAc)(3) assisted electrophilic addition of CH(3)SeSeCH(3) to 3',5'-di-O-benzoyl-2'-deoxyuridine. The 5-Se-T phosphoramidite was subsequently synthesized and incorporated into DNA in over 99% coupling yield. Biophysical and structural investigations of the 5-Se-T DNAs revealed that the Se-modified and nonmodified DNAs are virtually identical. In addition, the crystallographic analysis of a 5-Se-T DNA strongly suggests a hydrogen-bond formation between the 5-CH(3) and 5'-phosphate groups (CH(3)...PO(4)(-) interaction).
Organizational Affiliation: 
Department of Chemistry, Georgia State University, Atlanta, Georgia 30303, USA.