Objective: By adopting method of enzymatic reaction kinetics to investigate effects of bacuchiol on monophenolase and diphenolase activity of tyrosinase

and to inspect its mechanism and calculate kinetic parameters. Method: In the phosphate buffer system at 37℃ and pH of 6.8

absorbance was measured at 475 nm

the effect of bacuchiol on catalytic reaction of tyrosinase process was investigated

the inhibition rate of enzyme activity and kinetic parameters of bacuchiol were studied with L-tyrosine and L-dopa as substrate

respectively. Result: Bacuchiol could efficiently inhibit monophenolase and diphenolase activity of tyrosinase

their half inhibitory concentrations were 1.49 mmol·L-1 and 0.41 mmol·L-1

respectively.It was found that the inhibition type of diphenolase was a reversible inhibition.Lineweaver-Burk diagram showed that the inhibition effect of bacuchiol on diphenolase was a competitive behavior and its inhibition constant was 0.955 mmol·L-1. Conclusion: Compared with arbutin

the inhibition effect of bacuchiol on tyrosinase is more obvious in the low concentration range

so it worths developing into whitening products.