title: Effect of structural modification on photodynamic activity of hypocrellins.
abstract: Aluminum ion complexed 5,8-di-Br-hypocrellin B is a new water-soluble perylenequinonoid derivative with enhanced absorption over hypocrellin B (HB) in the phototherapeutic window (600-900 nm). Electron paramagnetic resonance and 9,10-diphenyl-anthracene bleaching methods were used to investigate the photosensitizing activity of [AL2(5,8-di-Br-HB)Cl4]n in the presence of oxygen. Singlet oxygen, superoxide anion radical and hydroxyl radical can be generated by [AL2(5,8-di-Br-HB)CL4]n photosensitization. Singlet oxygen (1O2) is formed via energy transfer from triplet-state [AL2(5,8-di-Br-HB)CL4]n to ground-state molecular oxygen. 1O2 participates in the generation of a portion of superoxide anion radical (O2.-). Besides superoxide anion radical (O2.-) may originate from the electron transfer between the triplet-state [AL2(5,8-di-Br-HB)CL4]n and the ground-state molecular oxygen. OH is formed through the Fenton-Haber-Weiss reaction and the decomposition of DMPO-1O2 adduct. Compared with HB [AL2(5,8-di-Br-HB)CL4]n primarily remains and enhances the generation efficiency of superoxide anion radical and hydroxyl radical but that of singlet oxygen decreases.
authors.affiliation: Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Jiang
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D017665:Hydroxyl Radical / Q000737:chemistry; D066298:In Vitro Techniques; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology*; D010100:Oxygen / Q000737:chemistry; D010569:Perylene / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D010777:Photochemistry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011809:Quinones / Q000737:chemistry / Q000494:pharmacology*; D026082:Singlet Oxygen; D013481:Superoxides / Q000737:chemistry
chemical_list: C437339:(Al2(5,8-dibromohypocrellin B)tetrachloride)n; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D011809:Quinones; D013481:Superoxides; D026082:Singlet Oxygen; D017665:Hydroxyl Radical; D010569:Perylene; D010100:Oxygen; C064522:hypocrellin B