Melanin production was significantly inhibited by arbutin, as determined by measuring eumelanin radicals with an electron spin resonance spectrometer.Thestudy of the kinetics and mechanism of inhibition of tyrosinase confirms the reversibility of arbutin
as a competitive inhibitor of this enzyme. The use of L-tyrosine or L-dihydroxyphenylalanine (L-DOPA) as a substrate suggests a mechanism involving competition with arbutin for the L-tyrosine binding site at the active site of tyrosinase.