Study on DNA-binding properties and cytotoxicity in L1210 of La(III) complex with PMBP-isonicotinoyl hydrazone

La(III) complex with 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone (PMBP)-isonicotinoyl hydrazone (La-complex) was synthesized in the work. The crystal of the La-complex was determined by X-ray diffraction analyses, the crystal of the complex is rhomb, space group R₃ with Z = 6, the coordination polyhedron of the complex is a tricapped triprism configuration with the nine-coordinate atoms, and the La-complex molecule looks like a helix structure according to its spacefill picture. Besides, it has been discovered that the La-complex possesses cytotoxic activities, and inhibitory rate for Leukemia cells (L₁₂₁₀) is 87.1%. The interaction of the La-complex with DNA was investigated by absorption spectrum, fluorescence, CD spectrum and viscosity measurements. The DNA-binding constant for the La-complex is (4.30 ± 0.14) × 10⁶ M⁻¹.