Racemic RS-4-(4-hydroxyphenyl)-2-butanol (rhododendrol, RD) was used as a topical skin-whitening agent until it was recently reported to induce leukoderma. We then showed that oxidation of RD with mushroom tyrosinase rapidly produces RD-quinone, which is quickly converted to RD-cyclic quinone and RD-hydroxy-p-quinone. In this study, we examined whether either or both of the enantiomers of RD can be oxidized by human tyrosinase. Using a chiral HPLC column, racemic RD was resolved optically to R(-)-RD and S(+)-RD enantiomers. In the presence of a catalytic amount of l-dopa, human tyrosinase, which can oxidize l-tyrosine but not d-tyrosine, was found to oxidize both R(-)- and S(+)-RD to give RD-catechol and its oxidation products. S(+)-RD was more effectively oxidized than l-tyrosine, while R(-)-RD was less effective. These results support the notion that the melanocyte toxicity of RD depends on its tyrosinase-catalyzed conversion to toxic quinones and the concomitant production of reactive oxygen species.
|Autori:||Rosaria Gangemi;Adriana Amaro;Alice Gino;Gaia Barisione;Marina Fabbi;Ulrich Pfeffer;Antonella Brizzolara;Paola Queirolo;Sandra Salvi;Simona Boccardo;Marina Gualco;Francesco Spagnolo;Martine J. Jager;Carlo Mosci;Armando Rossello;Silvano Ferrini|
|Titolo:||ADAM10 correlates with uveal melanoma metastasis and promotes in vitro invasion|
|Anno del prodotto:||2014|
|Digital Object Identifier (DOI):||10.1111/pcmr.12306|
|Appare nelle tipologie:||1.1 Articolo in rivista|