|Molar mass||211.173 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Topaquinone (TPQ) is a redox cofactor derived from the amino acid tyrosine. Its name derives from 2,4,5-trihydroxyphenylalanine-quinone. Its structure was first identified in 1990. It is used by copper amine oxidases which contain a tyrosine residue near the active site. This residue catalyses its own transition, first to dopaquinone and then to topaquinone, in a Cu2+ dependent manner.