Computational study of the reactivity of cytosine derivatives.

The aim of the present study is to provide computational insight using dispersion-corrected density-functional calculations into the reactivity properties of modified cytosine in the gas phase and in aqueous solution, whereby special emphasis is put on systems that are obtained through demethylation and methylation. Since this field is relatively incipient, our goal is to identify relationships between reactivity and stability for the modified compounds to understand their biological functionalities. Our results show that addition of a methyl, hydroxylmethyl, formyl, or carboxyl group reduces the length of the nearest hydrogen bond between the cytosine-guanine (CG) base pair and increases the length of the longest hydrogen bond of the DNA base pair. © 2017 Wiley Periodicals, Inc.