Light-induced processes in aqueous solutions of porphyrins

Ricardas Rotomskis; Giedre Streckyte; Saulius Bagdonas

doi:10.1117/12.230961

Translator Disclaimer

31 January 1996 Light-induced processes in aqueous solutions of porphyrins

Ricardas Rotomskis, Giedre Streckyte, Saulius Bagdonas

Author Affiliations +

Proceedings Volume 2625, Photochemotherapy: Photodynamic Therapy and Other Modalities; (1996) https://doi.org/10.1117/12.230961
Event: BiOS Europe '95, 1995, Barcelona, Spain

Abstract

An analysis of the spectral changes of porphyrins in aqueous solutions detected upon irradiation with visible light shows that a few photoprocesses take place. The decrease in absorption and emission intensity throughout the whole spectra reflects: (1) a photoinduced destruction of the porphyrin macrocycle and (2) a photoinduced chemical modification leaving the porphyrin macrocycle intact. The photodestruction of the porphyrin macrocycle is related to: (1) the formation of di- and mono-pyrrolic photoproducts absorbing in the UV and (2) the formation of negligible amounts of bilirubin-like photoproducts with the emission maximum at 545 nm. Another photoprocess is related to the formation of chlorin and bacteriochlorin type photoproducts with absorption maxima at about 640 - 660 nm, maintaining the porphyrin macrocycle intact. A scheme of the photomodifications of porphyrins is presented. The phototransformations of sensitizers should be taken into account in clinical photochemotherapy.

Citation Download Citation

Ricardas Rotomskis, Giedre Streckyte, and Saulius Bagdonas "Light-induced processes in aqueous solutions of porphyrins", Proc. SPIE 2625, Photochemotherapy: Photodynamic Therapy and Other Modalities, (31 January 1996); https://doi.org/10.1117/12.230961

ACCESS THE FULL ARTICLE