Aryl boronic acid inhibition of synthetic melanin polymerization.

Inhibitors of melanin formation are sought after for a range of applications. Boronophenylalanine is known to inhibit melanogenesis via boronic acid-catechol interactions. A spectroscopic assay was developed to study the polymerization of l-dopa to synthetic melanin in the presence of para-substituted aryl boronic acids. The best inhibition was observed for aryl boronic acids with electron-withdrawing substituents. The IC(50) values exhibit a correlation with the Hammett sigma(p) parameter (rho=0.97, r(2)=0.92). Copyright 2010 Elsevier Ltd. All rights reserved.