Photoproduct formation of endogeneous protoporphyrin and its photodynamic activity

摘要

Abstract: Human skin shows a strong autofluorescence in the red spectral region caused by the porphyrin production of the Gram positive lipophile skin bacterium Proprionibacterium acnes. Irradiation of these bacteria reduces the integral fluorescence intensity and induces the formation of fluorescent photoproducts. The fluorescence band (around 670 nm) and the decay times (around 1 ns and 5 ns) are typical for protoporphyrin products. The photoproduct formation is connected with an increased absorption in the red spectral region. However, the photodynamic activity of these photoproducts determined by scattering measurements on human erythrocytes is lower than that of protoporphyrin IX.!14