Pyrrolidonyl-β-naphthylamide (PYR) is a molecule used in

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

to detect the presence of

pyrrolidonyl peptidase Pyroglutamyl-peptidase I (, also known as Pyrrolidonyl peptidase, is an enzyme (a cysteine peptidase) found in bacteria, plants and animals. It can be used to distinguish certain Streptococcal organisms. Other names are ''5-oxoprolyl-peptidase'', ...

. In the presence of bacteria with pyrrolidonyl peptidase, it is broken down to pyroglutamic acid and

2-naphthylamine 2-Naphthylamine or 2-aminonaphthalene is one of two isomeric aminonaphthalenes, compounds with the formula C10H7NH2. It is a colorless solid, but samples take on a reddish color in air because of oxidation. It was formerly used to make azo dyes, b ...

. To detect this process, ''p''-dimethylaminocinnamaldehyde is added and a change to a pink color can then be detected.

References

Carboxamides Pyrrolidones Naphthylamines {{heterocyclic-stub