In contrast to the current view that kinetin (N 6-furfuryladenine) is an unnatural and synthetic compound, we have detected it in commercially available DNA, in freshly extracted cellular DNA from human cells and in plant cell extracts by two independent methods. First, we discovered that N 6-furfuryladenine has electrochemical properties that can be applied for monitoring this modified based by a HPLC/UV/EC method. Second, we have confirmed electrochemical assignments by mass-spectrometric analysis. A pathway of kinetin formation is proposed in which the formation of furfural by oxidative damage of the deoxyribose moiety of DNA is followed by its reaction with adenine residues to form N 6-furfuryladenine. Since this modification can lead to mutations, the odd DNA base has to be removed by repair enzymes.
