Synthesis of Some Polysubstituted Nicotinonitriles and Derived Pyrido[2,3-d]pyrimidines as In Vitro Cytotoxic and Antimicrobial Candidates

Table 1

Cytotoxic effects LC₅₀ (μM) of the active compounds on three human tumor and nontransformed cell lines and using the MTT assay.

Compound number	Human tumor cell lines			Nontransformed normal cell line
	Colon carcinoma (HT29)	Hepatocellular carcinoma (HePG2)	Breast cancer (MCF 7)	Foreskin fibroblast (Hs27)
21	70.5	—	—	NT
22	46.7	98.9	97.3	NT
23	62.2	—	—	NT
30	113.6	107	—	NT
32	153.4	111.3	123.0	NT
33	25.2	64.6	6.4	>200
34	28.8	70.1	7.9	>200
36	40.4	97.7	22.8	>200
37	26.9	71.2	8.91	>200
Doxorubicin	40.0	3.0	4.0	NT

LC₅₀: lethal concentration of the compound which causes death of 50% of cells in 24 h; totally inactive against this cell line; NT: not tested; Doxorubicin: positive control cytotoxic agent.