pH-dependent spectral behavior of substituted quinolones: potential fluorophore for metallofluorescent indicators.
The 7-methoxy and 7-hydroxy derivatives of 2,3-dimethyl-4-quinolone have been characterized with respect to absorbance, steady-state fluorescence excitation and emission, and acid-base behavior in perchloric acid (H(0) -5.68-pH 2.0) and aqueous buffers (pH 2.2-14.2); susceptibility to alkaline hydrolysis has been examined absorptiometrically. 7-Hydroxy-2,3-dimethyl-4-quinolone is resistant to attack by hydroxide ion. Aqueous solutions of it exhibit moderate to high fluorescence emission, which is dependent on solution acidity. It is recommended for incorporation into metallofluorescent indicators of the Calcein Blue type.
Huitink
G M
GM
Department of Chemistry, Indiana University South Bend, South Bend, IN 46634, USA.