Synthesis, Characterization and Antitumor Activity of Rare Earth Eu3+ and Dy3+ Complexes with Quercetin

The complexes of rare earth element Eu³⁺ and Dy³⁺ with quercetin were synthesized and characterized by elemental analysis, molar conductance, FTIR and UV-Vis spectra. The antitumor activities of the ligand and complexes were assayed against human hepatocarcinoma cell line HepG2 by MTT colorimetric assay. The results indicate that the formulas of the compounds are EuC₁₅H₈O₇Cl₁₀·6H₂O and DyC₁₅H₈O₇Cl₂·6H₂O. MTT assay showed that Quercetin, Eu³⁺-quercetin and Dy3+-quercetin dose dependently inhibited the proliferation of HepG2 cells, and the proliferation inhibition rates of cell treated with rare earth ion complexes of quercetin were significantly higher than those treated with quercetin. The antitumor activities of the complexes are markedly stronger than that of the ligand.