Synthesis, X-ray structure and anticancer activity evaluation of a binuclear La(III) complex with anthranilic acid

A binuclear La(III) complex {[La₂(HA)₄(H₂O)₄(C₂H₅OH)₂Cl₂]Cl₄ (C1)} with 2-aminobenzoic acid (HA) was prepared from the ligand and heptahydrated lanthanum chloride. The complex was characterised by X-ray crystallography that revealed anti-prismatic geometry around both of the lanthanum. In the complex, the four 2-aminobenzoic acid ligands are zwitter ionic and the two lanthanum(III) ions net charge is only counterbalanced by chloride ions. The complex cytotoxicity was determined against human breast (MDA-MB-231), prostate (PC-3) and bladder (T-24) cancer cells. This complex afforded cytotoxicity towards the T-24 bladder cancer cells with an IC₅₀ value of 383.5 µg/mL (319 µM). In contrary, activities by the lanthanum complex with IC₅₀ values of 1124 µg/mL (934 µM) and 739 µg/mL (614 µM) were, respectively, shown against the MDA-MB-231 and PC-3 cancer cells. This means the complex is more cytotoxic against the T-24 cells, despite that its activity is less compared with activities shown by classical drugs.