New complexes of usnate with lanthanides ions: La(III), Nd(III), Tb(III), Gd(III), synthesis, characterization, and investigation of cytotoxic properties in MCF-7 cells

Abstract

New lanthanides ions complexes were synthesized from the reactions of aqueous – ethanolic solution of the sodium usnate with an aqueous solution of the lanthanides ions. DFT data, UV–VIS spectroscopy, IR, 1H NMR, 13C NMR, HMBC, and elemental and thermal analyses, are consistent with the following general coordination formula: [LnL3(H2O)x], wherein L = C18H15O7–, Ln = Gd(III), Tb(III), x = 2 and Ln = La(III), Nd(III), x = 3. The chelates presented higher cytotoxic activity in breast cancer tumor cells (MCF-7) compared to organic and inorganic precursors. The two more potent compounds, complexes of La(III) and Gd(III), were tested in non-tumorigenic breast cells MCF-10A, showing less cytotoxicity, which evidenced their selectivity towards tumor cells.