Table 4.

In vitro antitumor activities of compounds 4a-4r.

Compd.	R3	IC50(μΜ)
		K562	HepG2
CPT		0.07 ± 0.01	0.37 ± 0.06
2m	C6H4-4-OCH3	0.03 ± 0.01	0.05 ± 0.03
4a	C6H4-3-OCH3	0.10 ± 0.03	1.89 ± 1.48
4b	C6H4-2-OCH3	0.37 ± 0.09	>10
4c	C6H4-3,5-(OCH3)2	0.51 ± 0.21	1.20 ± 0.58
4d	C6H4-3,4-(OCH3)2	0.26 ± 0.11	>10
4e	C6H4-4-CC3H9	2.25 ± 0.73	4.58 ± 1.09
4f	C6H4-4-F	0.24 ± 0.11	3.15 ± 2.31
4g	C6H4-4-Cl	0.23 ± 0.05	0.38 ± 0.21
4h	C6H3-3-Cl-4-F	0.38 ± 0.08	>10
4i	C6H4-4-CH3a	0.40 ± 0.12	>10
4j	C6H4-4-(O-Pr)	0.31 ± 0.08	>10
4k	C6H5	0.15 ± 0.02	1.08 ± 0.60
4l	C6H4-4-CNa	0.26 ± 0.04	0.89 ± 0.11
4m	C6H4-4-CF3a	0.35 ± 0.08	0.82 ± 0.20
4n	C6H4-4-OCF3a	0.06 ± 0.01	0.41 ± 0.32
4o	C6H4-4-OHa	0.06 ± 0.02	>10
4p	2-naphthyl	0.34 ± 0.10	>10
4q	4-pyridyl	0.04 ± 0.02	>10
4r	2-thiophenyl	0.08 ± 0.04	3.67 ± 1.40