Synthesis of novel derivatives of 5-hydroxymethylcytosine and 5-formylcytosine as tools for epigenetics

• Anna Chentsova,
• Era Kapourani and
• Athanassios Giannis

Beilstein J. Org. Chem. 2014, 10, 7–11, doi:10.3762/bjoc.10.2

• higher oxidation products such as 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) by the action of ten-eleven-translocation (TET) enzymes was discovered [9][10][11][12][13]. The TET proteins are identified as 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenases [10][14]. Whereas the DNA methylation

• catalyzed by TET enzymes followed by removal of 5fC and 5caC by thymine DNA glycosylase (TDG). Excision of 5fC and 5caC generates an abasic site, which is further repaired resulting in replacement of 5mC with unmodified cytosine (C) [15][16][17][18]. (2) The second alternative scenario still remains

• controversial [19][20]. It links the oxidative action of TET enzymes, the subsequent deamination of 5hmC to 5-hydroxymethyluracil (5hmU) by cytidine deaminases AID (activation-induced cytidine deaminase) or APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide) with the base excision repair (BER