Figure 1. Tyrosinase-based TLC autography activity assay. Column A (untreated sample), column B (melanin formation), column C (kojic acid), column D (quercetin), column E (gallic acid) and column F (chlorogenic acid).

Figure 1. Tyrosinase-based TLC autography activity assay. Column A (untreated sample), column B (melanin formation), column C (kojic acid), column D (quercetin), column E (gallic acid) and column F (chlorogenic acid).

Figure 2. Lineweaver-Burk plot of conversion of L-DOPA to dopachrome by tyrosinase in the presence and absence of bush tea extract.

Figure 3. Lineweaver-Burk plot of conversion of L-DOPA to dopachrome by tyrosinase in the presence and absence of kojic acid.

Figure 4. Lineweaver-Burk plot of conversion of L-DOPA to dopachrome by tyrosinase in the presence and absence of quercetin.

Figure 5. Lineweaver-Burk plot of conversion of L-DOPA to dopachrome by tyrosinase in the presence and absence of chlorogenic acid.

Table 1. Retention factor (Rf) of Athrixia phylicoides metabolites and kojic acid.

Table 1. Retention factor (Rf) of Athrixia phylicoides metabolites and kojic acid.

CompoundRetention Factor (Rf)Quercetin a0.94Gallic acid a0.85Unknown 1 a0.73Unknown 2 a0.44Chlorogenic acid a0.19Kojic acid b0.19

Table 2. IC50 values for inhibition of mushroom tyrosinase by Athrixia phylicoides metabolites and kojic acid.

Table 2. IC50 values for inhibition of mushroom tyrosinase by Athrixia phylicoides metabolites and kojic acid.

CompoundIC50 (µg/mL)Inhibitory Strength
(IC50I/IC50KA)A. phylicoidesa20.65 ± 0.143.96Quercetin a51.07 ± 2.439.78Chlorogenic acid a15.25 ± 1.182.92Kojic acid b5.22 ± 1.44NA