Glycosides Having Chromophores as Substrates for Sensitive Enzyme Analysis. II. Synthesis of Phenolindophenyl-β-D-glucopyranosides Having an Electron-Withdrawing Substituent as Substrates for β-Glucosidase

Five glucopyranosides, resorufinyl- (1), resazurinyl- (2), N-oxyphenolindophenyl- (3), phenolindo-3'-fluorophenyl- (4), and phenolindo-3'-azaphenyl-β-D-glucopyranoside (5), were synthesized through two routes. Compounds 1, 2, and 3 were synthesized by direct glycosidation of phenolindophenols. Compounds 4 and 5 were synthesized via the condensation of 4-aminophenyl 2, 3, 4, 6-tetra-O-acetyl-β-D-glucopyranosides (11 and 15) with p-quinone. These glucopyranosides (1-4) were hydrolyzed by β-glucosidase to give blue products showing high abseobance (ε : 22000-39000). They are considered to be potential substrates for the assay of β-glucosidase.