4-Nitrophenyl 2-acetamido-2-deoxy-4,6-O-p-methoxybenzylidene-a-D-galactopyranoside is a chromogenic substrate designed for the detection and quantification of enzyme activity. This methoxybenzylidene-protected compound is specifically designed to be cleaved by enzymes, releasing a yellow 4-nitrophenol product that can be easily measured spectrophotometrically. This allows for accurate and sensitive analysis of enzyme kinetics, inhibition studies, and substrate specificity determination in various applications.