Photobinding of Flutamide to Phospholipid Vesicles: additional Evidence for Photoprocesses unexpectedly triggered by conformational Changes in the Bilayer.

It is demonstrated that irradiation of the anticancer drug flutamide (FM) in presence of unilamellar phospholipid bilayer vesicles, chosen as a model for cell membranes, leads to an efficient photobinding process. This pathway is triggered by an unexpected hydrogen-abstraction reaction of the excited drug by the lipid chain and provides additional evidence that the overall photochemical scenario observed in the vesicles is unusually triggered by conformational change of the drug's molecular structure upon incarceration in the close-packed bilayer.The present investigation, beyond contributing to the general picture concerning fundamental aspects of the light-induced processes in self-organized assemblies, may also provide important insights for a more satisfactory understanding of the recently reported adverse photoallergic and phototoxic phenomena displayed by this anticancer drug.