Mutagenicity of a furocoumarin epoxide, heraclenin, in Chlamydomonas reinhardii.

Treatment of arg- or strd mutant cells of Chlamydomonas reinhardii with a furocoumarin epoxide, heraclenin, plus UV-A resulted in a decrease in survival and a UV-A dose-dependent increase in induced Arg+ or Strs revertants. Imperatorin, a furocoumarin with a very similar structure but lacking an epoxide group showed a very similar phototoxic and photomutagenic activity in these mutant strains. Treating the mutant cells with heraclenin or imperatorin in the dark neither influenced survival nor mutation induction. The results are discussed with respect to the involvement of the epoxide moiety of heraclenin in mutagenicity.