Di Yao

Synthesis, characterization, DNA/protein interaction and cytotoxicity studies of Cu(II) and Co(II) complexes derived from dipyridyl triazole ligands

Four different transition metal complexes containing dipyridyl triazole ligands, namely [Cu(abpt)2Cl2]·2H2O (1), [Cu(abpt)2(ClO4)2] (2), [Co2(abpt)2(H2O)2Cl2]·Cl2·4H2O (3) and [Co2(Hbpt)2(CH3OH)2(NO3)2] (4) have been designed, synthesized and further structurally characterized by X-ray crystallography, ESI-MS, elemental analysis, IR and Raman spectroscopy. In these complexes, the both ligands act as bidentate ligands with N, N donors. DNA binding interactions with calf thymus DNA (ct-DNA) of the ligand and its complexes 1~4 were investigated via electronic absorption, fluorescence quenching, circular dichroism and viscosity measurements as well as confocal Laser Raman spectroscopy. The results show these complexes are able to bind to DNA via the non-covalent mode i.e. intercalation and groove binding or electrostatic interactions. The interactions with bovine serum albumin (BSA) were also studied using UV-Vis and fluorescence spectroscopic methods which indicated that fluorescence quenching of BSA by these compounds was the presence of both static and dynamic quenching. Moreover, the in vitro cytotoxic effects of the complexes against four cell lines SK-OV-3, HL-7702, BEL7404 and NCI-H460 showed the necessity of the coordination action on the biological properties on the respective complex and that all four complexes exhibited substantial cytotoxic activity.

Study on the structural changes of bovine serum albumin with effects on polydatin binding by a multitechnique approach.

Polydatin is a traditional Chinese medicine which shows effective biological activity as antimicrobial and antiviral agent. The secondary structure changes of bovine serum albumin (BSA) were investigated by the methods of Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD) and Raman spectroscopy. The experimental results indicated that polydatin changed the secondary structure of BSA. The presence of polydatin decreased α-helix content of BSA. The conformations of disulfide bridges and the microenvironment of Tyr, Trp residues were also changed.

Syntheses and crystal structures of three pillared complexes based on H2AIP and triazole-bipyridine ligands

Three pillared polymeric complexes, {[Ni2(AIP)2(4,4′-bpt)(H2O)2]·4H2O}n (1), {[Co(AIP)(3,3′-bpt)]·H2O}n (2), and {[Ni(AIP)(3,3′-bpt)]·H2O}n (3) (H2AIP = 5-aminoisophthalic, 4,4′-bpt = 1H-3,5–bis(4-pyridyl)-1,2,4-triazole and 3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole), have been hydrothermally synthesized and characterized by X-ray diffraction analysis. Both 1 and 3 have 2-D (6,3) honeycomb layers, which are further interlinked by bent pillared triazole-bipyridine ligands to form a bilayer structure. The structures can be simplified to a (3,4)- and (3,5)-connected geometrical topology, respectively. Compound 2 has a Co-AIP layer structure in which the layers are pillared by 3,3′-bpt spacers to form the 3-D CsCl net.

Coordination Assemblies of CoII, NiII, ZnII, and CuII with 3,3′,4,4′-Biphenyltetracarboxylic Acid and Three Positional Isomeric Ligands

Eight different complexes with three positional isomeric dipyridyl ligands (3,3′-Hbpt, 3,4′-Hbpt, and 4,4′-Hbpt) (here, 3,3′-Hbpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole, 3,4′-Hbpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole, and 4,4′-Hbpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole), as well as 3,3′,4,4′-biphenyltetracarboxylic acid (H4bptc), namely, {[M(bptc)0.5(3,3′-Hbpt)(H2O)2]·H2O}n (M = Co (1), M = Ni (2)), {[Zn2(bptc)(3,3′-Hbpt)2]·3H2O}n (3), [Co(bptc)0.5(3,4′-Hbpt)(H2O)]n (4), [Ni(bptc)0.5(3,4′-Hbpt)2(H2O)2]n (5), {[Cu(bptc)0.5(3,4′-Hbpt)(H2O)]·H2O}n (6), and {[M(bptc)0.5(4,4′-Hbpt)2(H2O)]·4H2O}n (M = Co (7), and Ni (8)) were synthesised and characterised by single-crystal X-ray diffraction. The crystallographic analysis demonstrates that bptc influences the MII (M = Co, Ni, Cu, and Zn) ions to form 2D layers, which are further connected via the isomeric bpt connectors, leading to many types of coordination polymers, such as 2D layers(for 1–3, 5), 3D four-connected nets with a short Schlafli symbol of (64.82) (for 4, 6), and 3D four-connected nets with a short Schlafli symbol of (64.82)(5.63.72)0.5 (for 7–8). This work demonstrates that the isomeric effects of the bpt ligands influence the construction of these frameworks. The thermal stability of complexes 1–6 was investigated.