1993 年 41 巻 2 号 p. 314-318
Three novel N-acetyl-β-D-glucosaminides, 2', 7'-dichlorofluorescein mono(N-acetyl-β-D-glucosaminide) (6a), fluorescein mono(N-acetyl-β-D-glucosaminide) (6b) and 2', 7'-dichlorofluorescein di(N-acetyl-β-D-glucosaminide) (7a), were synthesized by the introduction of N-acetyl-β-D-glucosaminyl group into fluorescein derivatives followed by the removal of the protecting group. Compounds 6a, 6b and 7a were hydrolyzed by N-acetyl-β-D-glucosaminidase to give products showing high absorbance at a long absorption wavelength (500, 465 and 485 nm) under weakly acidic rate-assay conditions (pH 5.0). The Km values for 6a and 7a were 0.56 and 0.86 mM, respectively. Among these compounds, 7a is considered to be the most potential chromogenic substrate for the rate-assay of N-acetyl-β-D-glucosaminidase, since it gives a clear color generation from colorless to orange color (λmax 280→485 nm) by enzyme hydrolysis and has a higher water solubility of more than 30 mM.