TABLE 3.

Antiproliferative effects of tanshinone I derivatives (55, 92–106, 108–112, 128–140, 143–144, and 146) on human cancer cell lines.

Compound	IC50 (μM) a		Compound	IC50 (μM) a
	KB	KB/VCR		KB	KB/VCR
55	3.22 ± 0.65	2.95 ± 0.69	143	>20	>20
92	1.11 ± 0.30	0.51 ± 0.03	144	>20	>20
93	8.12 ± 3.19	5.71 ± 1.55	128	>20	>20
94	1.50 ± 0.09	1.02 ± 0.07	129	15.27 ± 0.10	1.99 ± 0.25
95	1.64 ± 0.30	1.43 ± 0.06	130	4.05 ± 0.05	2.47 ± 0.78
96	9.43 ± 6.18	10.88 ± 4.84	131	13.84 ± 1.37	5.17 ± 0.69
97	>20	>20	132	0.71 ± 0.16	0.92 ± 0.02
98	4.97 ± 3.01	2.41 ± 0.15	133	3.40 ± 0.78	2.64 ± 1.07
99	9.71 ± 4.88	4.74 ± 0.23	134	1.12 ± 0.49	1.53 ± 0.70
100	1.54 ± 0.31	1.11 ± 0.14	135	0.12 ± 0.02	0.33 ± 0.04
101	3.80 ± 0.40	3.82 ± 0.08	136	10.38 ± 3.43	3.52 ± 0.99
102	5.22 ± 0.77	13.12 ± 1.23	137	2.30 ± 0.54	1.56 ± 0.65
103	2.68 ± 0.26	4.41 ± 0.02	138	0.34 ± 0.22	1.72 ± 0.65
104	1.59 ± 0.16	1.79 ± 0.25	139	0.87 ± 0.11	1.49 ± 0.02
105	1.27 ± 0.26	0.91 ± 0.21	140	17.24 ± 1.72	10.07 ± 4.56
106	2.61 ± 0.08	1.70 ± 0.03	146	3.78 ± 1.23	1.65 ± 0.01
108	2.62 ± 0.23	2.37 ± 0.01	1	5.87 ± 0.70	4.40 ± 0.12
109	1.63 ± 0.03	1.24 ± 0.23	VCR (nM)	0.72 ± 0.16	357.51 ± 29.89
110	2.19 ± 0.49	2.02 ± 0.76
111	>20	>20
112	>20	>20

^aIC₅₀ values are shown as the mean ± SEM (μM) from two independent experiments.

Bold values represent tanshinone I-derived numbers.