Abstract
A 8,5′-cyclonucleotide was shown to be a product in the γ-radiolysis of oxygen-free aqueous solutions of adenosine-5′-monophosphate. Evidence for this was obtained by NMR-spectroscopy and chemical degradation to 8-formyladenine, 8-hydroxymethyladenine and 8-carboxyadenine. The chromatographic and spectral data of these compounds are given. Irradiation of other purinnucleotides leads to similar cyclonucleotides.