2,3-Diaminonaphthalene is an inhibitor of nitric oxide (NO) formation. The relatively nonfluorescent DAN reacts rapidly with the NO-derived N-nitrosating agent(s) to yield the highly fluorescent product 2,3-naphthotriazole (NAT). Has been used to develop enhanced detection

5-Aminonaphthalene-2-sulfonic acid inhibits Tyrosine-protein phosphatase non-receptor type 11 with an IC50 of 100 µM.