The structure and properties of 7-(2-oxoethyl)guanine: a model for a key DNA alkylation product of vinyl chloride.
Recent laboratory studies have shown that the major in-vivo DNA alkylation product of vinyl chloride is the 7-(2-oxoethyl) derivative of guanine, and the suggestion has been made that this derivative is responsible for the carcinogenicity of vinyl chloride. Some nuclear magnetic resonance evidence indicates that this alkylation product may be in equilibrium with a cyclic hemiacetal; this would affect the hydrogen bonding between guanine and cytosine. In order to help elucidate the properties of this key DNA alkylation product, we have computed the structure and properties of the same derivative of the isolated guanine molecule, i.e., 7-(2-oxoethyl)guanine. An ab initio self-consistent-field molecular orbital procedure was used. In this paper, we present the optimized (STO-3G) structure of 7-(2-oxoethyl)guanine, and the STO-5G energy, atomic charges and dipole moment. We found very little tendency for the formation of a cyclic hemiacetal; the equilibrium constant was estimated to be about 10(-9).
D004249:DNA Damage; D006147:Guanine / Q000031:analogs & derivatives*; D014752:Vinyl Chloride; D014753:Vinyl Compounds
D014753:Vinyl Compounds; D006147:Guanine; C032220:7-N-(2-oxoethyl)guanine; D014752:Vinyl Chloride