反应详情

To a 96-well plate, 40 μl of mushroom-derived tyrosinase (125 unit/ml; dissolved in a 67 mmol/l phosphate buffer solution; Sigma), 120 μl of 3,4-dihydroxyphenylalanine that serves as a substrate (L-dopa; 5 mmol/l; dissolved in a 67 mmol/l phosphate buffer solution; Sigma), and 40 μl of an inhibitor solution were added. The plate was allowed to stand for 37° C. for 30 minutes. Then, the amount of dopachrome produced was determined by absorbance at 490 nm. Tyrosinase inhibitory activity was expressed as an inhibitory rate obtained by the following equation: Inhibitory Rate (%)=[(A−B)−(C−D)]/(A−B)×100