Table 1.

Structure and antiproliferative activity of phthalascidin-related compounds

Analog	R1	R2	Cell line
			A-549	HCT116	A375	PC-3
Pt 650	CH3C(O)	A	0.95	0.38	0.17	0.55
1	CH3C(O)	D	3.2	0.59	0.35	0.64
2	CH3C(O)	C	1.5	0.85	0.27	1.1
3	CH3C(O)	B	1.2	0.61	0.35	0.75
4	CH3OCH2C(O)	A	1.6	0.87	0.31	0.90
5	CH3S(O)2	A	1.7	0.58	0.29	0.86
6	CH3CH2C(O)	A	2.1	1.2	0.51	2.9
7	CH3	A	3.1	1.4	0.55	3.1
8	CH3CH2	A	3.9	1.7	0.97	2.4
C15-Chloro-Pt 650			2.8	1.0	0.35	1.1
C15-, C18-p-Quinone-Pt 650			1.7	0.80	0.45	0.68
N12-[14C]-CH3-Pt 650			0.91	—	0.22	—
C21-OH-Pt 650			1.0	0.61	0.20	0.53
C21-H-Pt 650			2200	1100	610	850
C18-OMOM-Pt 650			230	74	66	98
Et 743			1.0	0.50	0.15	0.70

Values reported are IC₅₀ in nM.