Unknown

Inhibition of the diphenolase activity of mushroom tyrosinase was evaluated using L-DOPA as the substrate.2The test compounds (Orsellinic acid, compound 4) were first dissolved in dimethyl sulfoxide (DMSO) at 10.0 mM. For analysis of samples 4–14, 0.1 mL of sample solution in DMSO was combined with 1.5 mL of sodium phosphate buffer. Each resulting solution was then mixed with 0.2 mL of L-DOPA (3.5 mM) and 0.2 mL of tyrosinase (10 μg/mL). The mixtures were homogenized and incubated for 5 min at 30°C. Absorbances were measured at 475 nm to monitor the formation of dopachrome (ε=3700 M−1 cm−1) using a Spectrum 220 spectrophotometer.