Liping Lin

A dinuclear monofunctional platinum(II) complex with an aromatic linker shows low reactivity towards glutathione but high DNA binding ability and antitumor activity.

Multinuclear Pt(II) complexes represent a novel class of antitumor agents. In this work, a dinuclear monofunctional Pt(II) complex {[cis-Pt(NH3)2Cl]2(4,4′-methylenedianiline)}(NO3)2 (1) was synthesized and characterized by 1H NMR, electrospray mass spectrometry, and elemental analysis. The 2D [1H,15N] heteronuclear single quantum coherence NMR spectra of 15N-labeled 1 revealed that the cationic core of this water-soluble complex hardly hydrolyzes in aqueous solution and reacts very slowly with glutathione. Hydrolysis appears not to be an essential step for the formation of Pt–guanosine-5′-monophosphate (5′-GMP) or Pt–DNA adducts because the complex can react readily with 5′-GMP and partially transform B-DNA into its Z form. Such properties are desired to achieve the goal of enhancing cytotoxicity and lowering side effects of Pt(II) complexes. In fact, complex 1 is highly cytotoxic against the murine leukemia (P-388) and the human non-small-cell lung cancer (A-549) cell lines, and it is more cytotoxic than cisplatin at most concentrations tested.

Novel Au(III) complexes of aminoquinoline derivatives: crystal structure, DNA binding and cytotoxicity against melanoma and lung tumour cells

Three novel gold(III) complexes [Au(Quinpy)Cl]Cl (1), [Au(Quingly)Cl]Cl (2) and [Au(Quinala)Cl]Cl (3) [N-(8-quinolyl)pyridine-2-carboxamide = HQuinpy; N-(8-quinolyl)glycine-carboxamide = HQuingly; N-(8-quinolyl)-L-alanine-carboxamide = HQuinala] have been synthesized and characterized. The crystal structures of complexes 2 and 3 reveal that Au(III) is coordinated by three N atoms from the ligand and one Cl− anion. Complex 2 crystallized in the monoclinic system while complex 3 crystallized in the orthorhombic system. The complexes were tested against a series of tumour cell lines including B16-BL6, P388, HL-60, A-549 and BEL-7402. The data show that complex 1 is highly cytotoxic against the A-549 cells with an inhibition rate of 94.4% at a concentration of 10−6 mol L−1. Complex 3 is active against B16-BL6 with an inhibition rate of 67.52% at a concentration of 10−7 mol L−1. The interactions of complexes 1–3 with calf thymus (CT) DNA and 5′-GMP were investigated by UV-vis, fluorescence and ESMS spectroscopies. The data show that the interaction between Au(III) complexes and CT-DNA may be the intercalation effect, and complex 3 forms a 5′-GMP adduct as detected by ESMS.