Miaskiewicz K, Miller J, Osman R. Ab initio theoretical study of the structures of thymine glycol and dihydrothymine.
Int J Radiat Biol 1993;
63:677-86. [PMID:
8100254 DOI:
10.1080/09553009314552071]
[Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The structures of all diastereoisomers of 5,6-dihydroxy-5,6-dihydrothymine (thymine glycol) an 5,6-dihydrothymine, two important DNA lesions, have been optimized with ab initio quantum chemical methods at a 6-31 G level of calculations. The methyl group on C5 of thymine glycol shows a strong preference for a pseudo axial orientation. In contrast, in 5,6-dihydrothymine a pseudo equatorial methyl is preferred. Consequently, the thymine glycol lesion is much more bulky than 5,6-dihydrothymine. This observation may explain the different biological consequences observed for the two lesions.
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