Figures & data
Figure 1. Inhibition effects of hinokitiol on monophenolase activity of mushroom tyrosinase. (a) Progress curves for oxidation of l-Tyr by the enzyme. Concentrations of hinokitiol for curves 1–6 were 0, 1.6, 3.2, 4.0, 4.8, 6.4, and 8.0 μM, respectively. (b) Effects of hinokitiol on steady-state rate of monophenolase activity (curve 1) and lag period of mushroom tyrosinase (curve 2) for oxidation of tyrosine. Concentrations of enzyme and substrate (l-Tyr) were 6.67 μg/mL and 0.5 mM, respectively.
Figure 2. Effect of hinokitiol on diphenolase activity of mushroom tyrosinase.
Figure 3. Effects of tyrosinase concentration on its activity for oxidation of l-DOPA at different concentrations of hinokitiol. Concentrations of hinokitiol for curves 1–5 were 0, 0.13, 0.26, 0.40, and 0.53 μM, respectively.
Figure 4. Lineweaver–Burk plot for determination of inhibitory mechanism of hinokitiol on mushroom tyrosinase (I). Concentrations of hinokitiol for curves 1–4 were 0, 0.13, 0.26, and 0.40 μM, respectively. (II) and (III) represent plots of slope and intercept vs. concentration of hinokitiol for determining inhibition constants KI and KIS, respectively.
Figure 5. Effects of hinokitiol on cell vability, tyrosinase activity, and melanin content of B16 melanoma cells.
Figure 6. Antimicrobial activity of hinokitiol at different concentrations. Concentrations of hinokitiol for wells 1–5 were 10, 5, 2.5, 1.25, and 0.625 mg/mL, respectively. a, positive control with 2000 U/mL of streptomycin sulfate for bacterium; b, negative control with DMSO.
Table 1. Antimicrobial activity of hinokitiol.
Table 2. MIC and MBC (μg/mL) of hinokitiol.
