Showing papers by "Anju Chadha published in 1993"

Structures of covalent nucleoside adducts formed from adenine, guanine, and cytosine bases of DNA and the optically active bay-region 3,4-diol 1,2-epoxides of benz[a]anthracene

Abstract: Chemical structures of the principal covalent adducts formed from DNA upon reaction in vitro with the four optically active 3,4-diol 1,2-epoxides of benz[a]anthracene have been elucidated at the nucleoside level. In addition to adducts formed by cis and trans addition of the exocyclic amino groups of deoxyadenosine (dA) and deoxyguanosine (dG) and a trans deoxycytidine (dC) adduct, chemical characterization of a deglycosylated N-7 dG adduct formed in DNA by trans opening of the (4S,3R)-diol (2R,IS)-epoxide isomer is reported. Relative stereochemistries of the adducts (cis versus trans opening of the epoxides by the exocyclic amino groups) were deduced from the coupling constants of the methine protons of the tetrahydro benzo rings of the acetylated derivatives