Inhibition effects of benzylideneacetone, benzylacetone, and 4-phenyl-2-butanol on the activity of mushroom tyrosinase.

Tyrosinase (EC 1.14.18.1) is the key enzyme of melanin synthesis and fruit-vegetable browning. The inhibition of benzylideneacetone, benzylacetone, and 4-phenyl-2-butanol on mushroom tyrosinase was first investigated. The results shown that these three compounds could effectively inhibit the enzyme activity sharply and the inhibitory effects were determined to be reversible. Their inhibitor concentrations leading to 50% activity lost values were determined to be 1.5, 2.8, and 1.1 mM for monophenolase and 2.0, 0.6, and 0.8 mM for diphenolase, respectively. For the monophenolase activity, all of these three compounds were mixed-type inhibitors, however, only 4-phenyl-2-butanol obviously lengthened the lag time. For the diphenolase activity, benzylideneacetone and benzylacetone were mixed-type inhibitors, while 4-phenyl-2-butanol was a noncompetitive type inhibitor. In conclusion, these compounds exhibited potent antityrosinase activities. This research would provide scientific evidence for the use of benzylideneacetone, benzylacetone, and 4-phenyl-2-butanol as antityrosinase agents.