SINGLET OXYGEN PRODUCTION BY SOME FUROCOUMARIN DERIVATIVES IN THE PRESENCE OF DNA: TIME RESOLVED LUMINESCENCE MEASUREMENTS

Abstract
Abstract—The yield of singlet oxygen (1Δg) from some furocoumarins in the presence of DNA has been measured using time resolved techniques. For both psoralen and 4'‐aminomethyl‐4,5',8‐trimethylpsoralen, increasing DNA concentration leads to a decrease in the yield of singlet oxygen. In addition, there is a linear dependence between the yield of singlet oxygen and the observed triplet yield determined by laser flash photolysis. In view of this observation it seems unlikely that singlet oxygen production occurs from these two furocoumarins when they are complexed with DNA. Preliminary, albeit inconclusive, results for 8‐methoxypsoralen are also presented.