Mechanism of skin photosensitization by forucoumarins. Photoreactivity of various furocouma- rins with native DNA and with ribosomal RNA.

Abstract

Abstract The photoreactions (by irradiation at 365 nm) between several furocoumarins and native DNA or rRNA have been studied. The initial rates of the photoreactions and the quantum yields were determined. Moreover some experiments have been performed in a manner suitable to give data of photoreactivity which could be directly compared with those previously obtained in determining the skin-photosensitizing activity of the same substances by irradiation at 365 nm. The results showing a close correlation between the capacity of the substances to photoreact with native DNA and that to produce skin photosensitization, offer valid evidence for the mechanism of action of furocoumarins on the skin. By contrast, the photoreactions with rRNA seem to be less (or not) connected with skin photosensitization.