The photochemistry of purine components of nucleic acids. I. The efficiency of photolysis of adenine and guanine derivatives in aqueous solution.

It has been shown that the quantum yield of the photochemical conversion of adenine and the corresponding nucleosides and nucleoside 5'-phosphates in liquid (pH 5.6 and 2.0) and frozen aqueous solutions do not exceed 10(-4). The quantum yield of the photoconversion of guanine-containing nucleosides and nucleoside 5'-phosphates in liquid aqueous solution (pH 5.6) after removal of oxygen by passing through nitrogen and in the frozen state do not exceed 0.3 x 10(-4). The quantum yield in oxygen-containing liquid aqueous solutions increase to 0.3 x 10(-3), i.e. to values commensurate with the quantum yield of pyrimidine photolysis.