Colorimetric assays for N-acetyl-beta-D-glucosaminidase and beta-D-galactosidase in human urine using newly-developed omega-nitrostyryl substrates.

(1) The synthesis of 2-methoxy-4-(2'-nitrovinyl)-phenyl 2-acetamido-2-deoxy-beta-D-glucopyranoside (MNP-GlcNAc) and 2-methoxy-4-(2'nitrovinyl)-phenyl beta-D-galactopyranoside (MNP-Gal) as substrates for the assay of NAG and beta-d-galactosidase are described. (2) beta-Glycosidase activities were determined in random urine samples from normal males and females aged between 12 and 87 years and patients with renal disease. (3) Both the MNP N-acetylglucosaminide and MNP galactoside were stable indefinitely, if stored in the solid state at 4 degree C in the dark.