DNA-Like Duplex Structures Derived from Chemistry Based on 2’-Deoxy-Cytidine: A New Model for Base-Specific Inhibition of G and C on DNA and RNA Level

The new epigenetic elements 5-hydroxymethyl-dC, 5-formyl-dC, and 5-car- boxy-dC may be considered as intermediates of an active demethylation process. A comprehensive mechanistic model is given for the C-C bond cleavage focused on the chemistry within the DNA duplex structure. In addition we register spin-off chemistry of this process in evaluating new duplex systems closely related to natural DNA and RNA concerning their hydrogen-bond symmetrization. A model is composed for a base-specific inhibition of G and C on the DNA and RNA level. C-G combinations are of general importance in controlling the dynamics of gene expression. In some way the suggested model systems are related to antisense oligonucleotides (ASOs).