49784-82-9Relevant academic research and scientific papers
Substituent effects on the chemiluminescent properties of coelenterazine analogues
Saito, Ryota,Hirano, Takashi,Niwa, Haruki,Ohashi, Mamoru
, p. 95 - 96 (1998)
Chemiluminescence maxima and quantum yields of coelenterazine analogues possessing a substituent R [= CF3, F, H, OCH3, OH, N(CH3)2] at the para-position on the 6-phenyl group were measured in DMSO. The result in
Solvent and substituent effects on the fluorescent properties of coelenteramide analogues
Saito, Ryota,Hirano, Takashi,Niwa, Haruki,Ohashi, Mamoru
, p. 1711 - 1716 (2007/10/03)
Coelenteramide 1 is the light emitter in aequorin bioluminescence. To establish the fluorescent character of 1, the fluorescence properties of 1 and a series of its analogues, 3a-f, possessing a substituent R [= CF3, F, H, OCH3, OH, N(CH3)2] at the para-position on the 5-phenyl group have been investigated in solvents of various polarity. The fluorescence emission maxima of 1 and 3d-f, possessing an electron-donating group R [= OCH3, OH, N(CH3)2] shift to lower energy with increasing solvent polarity, while those of the analogues 3a-c (R = CF3, F, H) are independent of the solvent polarity. The linear correlation between the fluorescence maxima of 1 and 3d-f and the solvent polarity scales can be explained by formation of the singlet excited state with a charge-transfer (CT) character. The quantum yields of CT fluorescence of 1 and 3d-f have been found to be higher than those of 3a-c. These results indicate that the solvatochromic fluorescence of 1 originates from the CT excited state and the existence of an electron donating hydroxy group on the 5-phenyl group is essential for determining a wavelength and a high fluorescence quantum yield of aequorin bioluminescence.
