Effects of Chloride, Bromide, and Iodide Upon Decomposition of Nucleosides Induced by Ultrasound in Neutral Solution

Abstract

When the ultrasound of 42 kHz was irradiated on a neutral mixture of 2′-deoxycytidine, 2′-deoxyguanosine, 2′-deoxythymidine, and 2′-deoxyadenosine, concentrations of all the nucleosides decreased. Addition of NaCl to the system had no effect. NaBr suppressed the reactions for all the nucleosides, but the efficiency of 2′-deoxyguanosine was low. NaI suppressed the reactions for all the nucleosides more effectively. A comparison with the results of the effects of halides on the reaction of nucleosides by a Fenton system suggested that only half of the nucleoside damage in the ultrasound-irradiated solution was caused by hydroxyl radicals formed from water by the sonication.

Keywords:

• Ultrasound
• nucleoside
• halide
• hydroxyl radical
• hydrogen radical

Present address of Kenji Yamada: Okayama University, Okayama 700-8530, Japan.

Notes

^a A solution of dCyd, dGuo, dThd, and dAdo (100 μM each) with 100 mM potassium phosphate buffer (pH = 7.4) in a micro tube was incubated with 5 mM FeSO₄ and 10 mM H₂O₂ in the presence of 100 mM halides at 37°C for 60 minutes. The nucleoside concentrations were determined by RP-HPLC analysis. Means ± SD (n = 3) are shown.