tyrosinase activity was reduced with decreasing copper concentration, when mushroom-derived tyrosinase, a metalloprotein containing copper, was incubated with ellagic acid.
Since ellagic
acid is known to chelate some specific metal ions, it is presumed to react specifically with the copper located at the
active site of the tyrosinase molecule. Ellagic acid is a naturally occurring polyphenol, which is found widely
distributed in plants such as tara, green tea, eucalyptus, and geranium. These two active ingredients are examples of
natural-origin compounds being used as skin-whitening agents.