Synthesis, Spectroscopic Characterization, Structural Studies, and In Vitro Antitumor Activities of Pyridine-3-carbaldehyde Thiosemicarbazone Derivatives

Table 4

Selectivity of the cytotoxicity of the pyridine-3-carbaldehyde thiosemicarbazone derivatives (1–8) to tumor cells, as compared with 3T3 non-tumor cells.

Compound	Selectivity index^a (SI)
	H460	HuTu80	DU145	MCF-7	M-14	HT-29
5-FU ^b	<0.13	<0.13	<0.06	<0.19	<0.06	<0.10
1	0.56	0.85	0.29	0.98	1.82	0.54
2	NC	NC	NC	NC	NC	NC
3	NC	>1.50	1.00	NC	NC	NC
4	0.62	1.51	0.91	0.83	0.43	0.26
5	0.47	0.61	0.57	0.32	<0.06	0.25
6	<1.00	2.49	1.00	1.54	<1.00	1.00
7	0.66	1.33	0.92	1.11	1.65	1.25
8	NC	NC	NC	NC	NC	NC

^aThe selectivity index is the ratio of the IC₅₀ values of the compounds on 3T3 cells to those in the tumor cell lines. NC = unable to calculate. ^b5-Fluorouracile.