Table 3.

Inhibition against four marine phytoplankton species by 1–11.

Compound	IC50 (μg/mL)
	Chattonella marina	Heterosigma akashiwo	Karlodinium veneficum	Prorocentrum donghaiense
1	5.2	8.0	10	9.9
2	8.8	21	76	6.5
3	61	73	71	40
4	13	73	6.3	34
5	2.4	26	3.9	20
6	5.8	37	5.5	15
7	59	14	35	7.3
8	42	50	12	3.4
9	15	53	43	1.1
10	1.6	1.8	1.6	2.0
11	62	9.4	13	6.0