Enhanced cell permeability of kojic acid-phenylalanine amide with metal complex.

Kojic acid-phenylalanine amide (KA-F-NH(2)), which showed an excellent tyrosinase inhibitory activity, did not inhibit melanogenesis in melanocyte due to its low cell permeability. To enhance its cell permeability by increasing lipophilicity, we prepared metal coordination compounds of KA-F-NH(2) and characterized them by FT-IR and ICP analysis. The metal complex of KA-F-NH(2) inhibited mushroom tyrosinase activity as much as KA-F-NH(2) and reduced melanin contents in melanocyte efficiently.