title: Photodynamic action of some sensitizers by photooxidation of luminol.
abstract: We report the development of a novel simple experimental method which allows the comparison of new photosensitizers based on their production of reactive oxygen species. A high-performance liquid chromatography (HPLC) assay permits the monitoring of several substances (sensitizer, reactant and oxidized end product) simultaneously on a single chromatogram. Photoreactions were monitored throughout their course by the HPLC assay surveying the sensitizers' efficiency of singlet oxygen production by the oxidative decomposition of luminol. Several photosensitizers were tested: Rose Bengal, Methylene Blue, Protoporphyrin IX, Photosan III, Photofrin, Hypericin and Pseudohypericin. Additionally, photoreactions were monitored by a standard pO(2) detection system. The measurements of the two detection methods were strongly correlated. Rose Bengal proved to be the most efficient photosensitizer, clearly decreasing the luminol concentration and causing a corresponding increase in aminophthalic acid. Our experiments show that when factors necessary for photochemical reactions are absent or are blocked (antioxidants), no reaction can be detected.
authors.affiliation: Viennese Society for Photophysical Diagnosis and Photodynamic Therapy, Juchgasse 25, 1030 Vienna, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Wierrani
authors.forename: Andreas
authors.initials: A
authors.lastname: Kubin
authors.forename: Hans Günter
authors.initials: HG
authors.lastname: Loew
authors.forename: Michael
authors.initials: M
authors.lastname: Henry
authors.forename: Babette
authors.initials: B
authors.lastname: Spängler
authors.forename: Klaus
authors.initials: K
authors.lastname: Bodner
authors.forename: Werner
authors.initials: W
authors.lastname: Grünberger
authors.forename: Robert
authors.initials: R
authors.lastname: Ebermann
authors.forename: Gerhart
authors.initials: G
authors.lastname: Alth
mesh_terms: D017323:Dihematoporphyrin Ether / Q000737:chemistry; D004355:Drug Stability; D008165:Luminol / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000737:chemistry*; D012395:Rose Bengal / Q000737:chemistry; D012997:Solvents
chemical_list: D017319:Photosensitizing Agents; D012997:Solvents; D012395:Rose Bengal; D008165:Luminol; D017323:Dihematoporphyrin Ether; D008751:Methylene Blue