Sugar conformational effects on the photochemistry of thymidylyl(3'-5')thymidine.
The synthesis and conformational analysis of 2'-O,5-dimethyluridylyl(3'-5')-2'-O,5-dimethyluridine (1a), the analogue of thymidylyl(3'-5')thymidine (TpT; 1b) in which a methoxy group replaces each 2'-alpha-hydrogen atom, are described. In comparison with TpT, such modification increases the population of the C3'-endo conformer of the sugar ring puckering at the 5'- and 3'-ends from 30 to 75% and from 37 to 66%, respectively. Photolyses of 1a and TpT at 254 nm are qualitatively comparable (the cis-syn cyclobutane pyrimidine dimer and the (6-4) photoproduct are formed), although it is significantly faster in the case of 1a. These results are explained by the increased propensity of the modified dinucleotide to adopt a base-stacked conformation geometry reminiscent of that for TpT.
Ostrowski
Tomasz
T
Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91190 Gif sur Yvette, France.
Maurizot
Jean-Claude
JC
Adeline
Marie-Thérèse
MT
Fourrey
Jean-Louis
JL
Clivio
Pascale
P
D002236:Carbohydrate Conformation; D002942:Circular Dichroism; D003855:Deoxyribose / Q000737:chemistry*; D015226:Dinucleoside Phosphates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010777:Photochemistry
D015226:Dinucleoside Phosphates; C017758:thymidylyl-(3'-5')-thymidine; D003855:Deoxyribose