Table 3.

Relative potency of the investigated compounds in the panel of human tumor cell line K-562, following 48-hour treatment (MTT-dye reduction assay).

Compound	IC50 value (a)
Sm(CCA)2(NO3) · H2O	108.39 ± 6.9 μM
Gd(CCA)2(NO3) · H2O	164.52 ± 11.23 μM
Dy(CCA)2(NO3) · H2O	>200 μM
Sm(NO3)3 · 6H2O	>200 μM
Gd(NO3)3 · 6H2O	41.35 ± 5.9 μM
Dy(NO3)3 · 5H2O	76.78 ± 4.72 μM

^(a)Data represent the arithmetic mean ± standard deviation of six independent experiments.