Tyrosinases are ubiquitous Cu-containing enzymes belonging to the type-3 or “coupled binuclear” family (Fig. 1). Ty’s catalyze the two-step oxidation of phenolic compounds into the corresponding catechols (monophenolase activity) and ortho-quinones (catecholase activity). In mammals, their biological function is to convert L-tyrosine into dopaquinone, which is the key product for melanin pigment biosynthesis. Melanin-related disorders are known to cause serious skin lesions, Parkinson’s disease and melanoma. In addition, Ty’s are responsible for the browning of plant foods, which creates an important economic problem in the field of nutrition. Ty inhibition is a well-established approach for controlling in vivo melanin production and food browning, so the development of Ty inhibitors has a huge economical and industrial impact. To control the Ty activity, the best strategy is to target the Ty binuclear copper active site by transition state analogues, which have structural analogies to catechol but are not oxidizable. Recently, we reported on HOPNO as TS analogues featuring competitive inhibition constants below to 1 .1 In this communication, we will describe our strategy to develop efficient Ty inhibitors derived from HPNO and aurones. Our approach includes synthetic chemistry and enzymology as well as structure-function studies using structural and functional models (Fig. 3) of the Ty active site.2-9figureFigure 1. Structure of the active site of the met2 Ty. Figure 2. HOPNO and aurones (1-2). Figure 3. Ty structural model in interaction with HOPNO.