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

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, (HNMR)-H-1, C-13 NMR, HMBC, and elemental and thermal analyses, are consistent with the following general coordination formula: [LnL(3)(H2O)(x)], wherein L = C(18)H(15)O7(-), 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.