4-Amino-1-naphthalenesulfonic acid has potent therapeutic applications. Its sodium salt has been used as non-toxic hemostatic. It is also a metabolite of azo dyes.
Alonso, M., et al.: Anal. Chim. Acta, 400, 211 (1999); Chung, K., et al.: Appl. Environ. Microb., 42, 641 (1981)