title: Photophysical property of sanguinarine in the excited singlet state.
abstract: The photophysical property of the alkanolamine form of sanguinarine has been studied in aqueous and organic medium under various environmental conditions from the measurement of absorption, fluorescence and NMR spectroscopy. Alkanolamine fluorescence shows an excitation time dependent fluorescence quenching and the rate of quenching increases significantly with increasing pH and concentration of the species, while it decreases with increasing temperature. This phenomenon is explained by excited state intramolecular proton transfer from a 6-OH group to the lone pair of nitrogen through the formation of zwitterion.
authors.affiliation: Biophysical Chemistry Laboratory, Indian Institute of Chemical Biology, Calcutta.
authors.forename: A
authors.initials: A
authors.lastname: Das
authors.forename: R
authors.initials: R
authors.lastname: Nandi
authors.forename: M
authors.initials: M
authors.lastname: Maiti
mesh_terms: D000470:Alkaloids / Q000737:chemistry* / Q000528:radiation effects; D000890:Anti-Infective Agents / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry*; D053119:Benzophenanthridines; D007546:Isoquinolines; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013050:Spectrometry, Fluorescence / Q000379:methods; D013053:Spectrophotometry / Q000379:methods
chemical_list: D000470:Alkaloids; D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D053119:Benzophenanthridines; D007546:Isoquinolines; C005705:sanguinarine