Table 2.
Inhibition constants of C. cassia essential oil (CC-EO), trans -cinnamaldehyde and cis -2-methoxycinnamic acid for mushroom tyrosinase
| Inhibitor | CC-EO | trans-cinnamaldehyde | cis-2-methoxycinnamic acid |
|---|---|---|---|
| IC50 (mg/mL) | 6.16 ± 0.04a* | 4.04 ± 0.08* | NS |
| Ki (mg/mL) | 4.71 ± 0.09* | 2.38 ± 0.09* | NT |
| αKi (mg/mL) | 15.50 ± 0.49* | 9.61 ± 0.47* | NT |
| Inhibition type | Mixed | Mixed | NT |
aValues are presented as mean ± S.D. (n = 3). NS: tyrosinase inhibitory effect not shown; NT: not tested.
*Means in the same parameter are significantly different (p < 0.05). Ki: dissociation constant for inhibitor binding with the free enzyme; αKi: dissociation constant for inhibitor binding with the enzyme-substrate complex.