title: Spectroscopic Properties of Amine-substituted Analogues of Firefly Luciferin and Oxyluciferin.
abstract: Spectroscopic and photophysical properties of firefly luciferin and oxyluciferin analogues with an amine substituent (NH2, NHMe and NMe2) at the C6' position were studied based on absorption and fluorescence measurements. Their π-electronic properties were investigated by DFT and TD-DFT calculations. These compounds showed fluorescence solvatochromism with good quantum yields. An increase in the electron-donating strength of the substituent led to the bathochromic shift of the fluorescence maximum. The fluorescence maxima of the luciferin analogues and the corresponding oxyluciferin analogues in a solvent were well correlated with each other. Based on the obtained data, the polarity of a luciferase active site was explained. As a result, the maximum wavelength of bioluminescence for a luciferin analogue was readily predicted by measuring the photoluminescence of the luciferin analogue in place of that of the corresponding oxyluciferin analogue.
authors: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors: Michio
authors: M
authors: Kakiuchi
authors: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors: Soichiro
authors: S
authors: Ito
authors: Division of Molecular Science, Graduate School of Science and Engineering, Gunma University, Kiryu, Gunma, Japan.
authors: Minoru
authors: M
authors: Yamaji
authors: Department of Physics, Chemistry and Mathematics, Graduate Program of Biotechnology and Environmental Monitoring, Federal University of São Carlos (UFSCAR), Itinga, Sorocaba, SP, Brazil.|Graduate Program of Evolutive Genetics and Molecular Biology, Federal University of São Carlos (UFSCAR), São Carlos, SP, Brazil.
authors: Vadim R
authors: VR
authors: Viviani
authors: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors: Shojiro
authors: S
authors: Maki
authors: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors: Takashi
authors: T
authors: Hirano
mesh_terms: D000588:Amines / Q000737:chemistry*; D049454:Firefly Luciferin / Q000031:analogs & derivatives / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D049409:Luciferases, Firefly / Q000737:chemistry; D049449:Luminescence; D066244:Proton Magnetic Resonance Spectroscopy; D011719:Pyrazines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D000588:Amines; D007211:Indoles; D011719:Pyrazines; D012997:Solvents; C014730:oxyluciferin; D049454:Firefly Luciferin; D049409:Luciferases, Firefly