Table 1. Tyrosinase inhibitory activity of test compounds before and after plasma treatment.

Samples	IC50(μg/ml)
	4a	4b	4c	4d	4e	6a	6b
Con	25 ± 3	29 ± 5	15 ± 4	58 ± 7	19 ± 2	5 ± 2	7 ± 2
3 min	24 ± 3	24 ± 7	19 ± 5	47 ± 4	77 ± 7	5 ± 2	33 ± 5
5 min	20 ± 5	23 ± 2	24 ± 6	36 ± 3	72 ± 7	5 ± 2	40 ± 6
10 min	17 ± 1	14 ± 2	29 ± 4	29 ± 2	56 ± 3	3 ± 1	55 ± 5

IC₅₀ for tyrosinase inhibition activity was determined for all test compounds (4a, 4b, 4c, 4d, 4e, 6a, and 6b) before and after plasma treatment (3, 5, and 10 min). All data were expressed as mean ± standard deviation.