4-Nitrophenyl α-D-Mannopyranoside is used extensively in biochemical research as a chromogenic substrate to study enzyme mechanisms, particularly α-mannosidases, a type of glycosidase. The hydrolysis by these enzymes releases 4-nitrophenol, which can be quantified by spectrophotometry, enabling precise investigation of enzyme activity and specificity. It is applied in the development of diagnostic assays for enzyme-related diseases. Also utilized in carbohydrate chemistry to explore glycosylation processes and the synthesis of complex carbohydrates. Its role in understanding cell surface interactions and carbohydrate recognition makes it valuable in immunology and glycobiology studies.