Tyrosinase Inhibition by Dienols

Small molecule dienols’ (4a–e) tyrosinase inhibition activity were assayed using a modified protocol by Chen et al. and compared to that of free KA in vitro.^{9 (link)} Mushroom tyrosinase inhibition was determined by adding dienols in sample media (25 µL) to 96-well plates containing phosphate buffer (80 µL, pH = 6.8) and 125 µL substrate (0.5 mM L-DOPA) and incubated for 5 min at room temperature.^{9 (link)} Mushroom tyrosinase (20 µL, 1250 U/mL, Sigma, Milwaukee, WI) in phosphate buffer (pH = 6.8) was added and incubated an additional 5 min at room temperature. The amount of dopachrome produced was measured using a microplate reader (Coulter, Boulevard Brea, CA) at 475 nm. Dienol (4a–e) tyrosinase inhibition was expressed as a function of the dienol concentration and inhibitory concentration 50 (IC₅₀) values calculated and compared to KA (positive control).