In vitro cytotoxicity
The in vitro cytotoxic potency of thiourea a-aminophosphonate
derivatives 4e5 were evaluated by MTT assay against NCI-H460,
HepG2, A549 and SKOV3 tumor cell lines (with 5-fluorouracil (5-
FU) as the positive control). The values of IC50, the effective concentration
at which 50% of the tumor cells were inhibited, were
calculated to evaluate the antitumor activities. A lower IC50 value
indicated greater antitumor activity. IC50 values of lower than that
of control usually implied effective antitumor activity. The tested
results were shown in Table 1.