Used as a chromogenic substrate in enzymatic assays, particularly for detecting aminopeptidase activity. When cleaved by the target enzyme, it releases beta-naphthylamine, which can be coupled with a diazonium salt to produce a colored end product, enabling visual or spectrophotometric detection. Commonly applied in clinical diagnostics and research settings to assess enzyme activity in biological samples. Also utilized in microbiology for bacterial identification based on enzymatic profiles.