Abstract

A comparative study is performed of the effect an inorganic phosphate (P_i) has on the formation of hydrogen peroxide in aqueous solutions of 2 × 10⁻⁴ M adenine derivatives (AX), such as adenine, adenosine, and adenosine-5'-diphosphate, irradiated at 77 K by near-UV in the wavelength range λ = 260–400 and 290–460 nm. It is found that the yield of H₂O₂ in irradiated samples grows upon adding 5 × 10⁻⁴ M P_i. The yield of H₂O₂ is normally increased in the presence of NaCl, while a tenfold increase in [P_i] results in only a moderate rise in [H₂O₂]. It is shown that the effect irradiation has on the yield of H₂O₂ depends on both AX and the [NaCl] and [P_i] ratio. The obtained data are compared to the results from measuring the EPR spectra of irradiated solutions before defrosting. Possible mechanisms of photoinitiated processes of H₂O₂ formation in the studied systems are discussed.

中文翻译：

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无机磷酸盐在 77 K 腺嘌呤衍生物水溶液中过氧化氢光生成中的作用

摘要

对无机磷酸盐 (P _i ) 在 2 × 10 ^-4 M 腺嘌呤衍生物 (AX) 的水溶液中形成过氧化氢的影响进行了比较研究，例如腺嘌呤、腺苷和腺苷-5'-二磷酸盐，在波长范围 λ = 260-400 和 290-460 nm 的近紫外线下在 77 K 下照射。发现辐照样品中H ₂ O ₂的产率随着添加5×10 ^-4 MP _{i 增加}。H ₂ O ₂的产量在 NaCl 存在下通常会增加，而 [P _i ]的十倍增加只会导致 [H ₂ O ₂]。结果表明，辐照对H ₂ O ₂产率的影响取决于AX 以及[NaCl] 和[P _i ] 的比率。将获得的数据与在解冻前测量辐照溶液的 EPR 光谱的结果进行比较。讨论了所研究系统中H ₂ O ₂形成的光引发过程的可能机制。