Alteration in the molecular structure of the adenine base exposed to gamma irradiation: An ESR study

Abstract

Adenine polycrystals were obtained from their powder form under effective crystallization conditions by adjustment of the concentration of chemical solutions. The adenine samples were irradiated with a 60Co gamma-ray source at room temperature for 12, 24, 48, and 72 h, and then these samples were investigated between 240 and 400 K using an electron spin resonance (ESR) spectrometer. No signals were observed in the non-irradiated samples irradiated for 12, 24, and 48 h; however, when irradiated for 72 h, the samples exhibited complex ESR spectra. The analysis indicated the presence of a radical structure, NH \dot{{NH}} . The hyperfine splitting and g-values were calculated from the spectra by simulation programs. Also, during the measurements, it was observed that the shapes of the ESR lines changed slightly with the temperature.