Synthesis, structure and properties of unsymmetrical μ-alkoxo-dicopper(II) complexes: biological relevance to phosphodiester and DNA cleavage and cytotoxic activity

The crystal structure, self-assembly, DNA-binding and cleavage studies of the [2]pseudorotaxane composed of cucurbit[6]uril

The [2]pseudorotaxanes of cucurbit[6]uril with guest molecule 1,6-bis(imidazol-1-yl)hexane (BIMH) were synthesized and characterized by ESI-MS spectrometry, (1)H NMR spectra, and X-ray diffraction crystallography. The influence of different anions on self-assembly in solid-state was discussed by X-ray diffraction crystallography. However, more interestingly, and to our amazement, we discovered the CB[6]/BIMH [2]pseudorotaxane exhibiting efficient cleavage of pBR322 DNA in physiological environment. The cleavage mechanism were studied by fluorescence spectra and the hydrolysis of bis(2,4-dinitrophenyl)-phosphate (BDNPP). From DNA-binding mode being electrostatic force and the first-order kinetics equation, we prove indirectly that the mechanism may be hydrolytic cleavage.

Synthesis, crystal structure, magnetic property and nuclease activity of a new binuclear cobat(II) complex

One new binuclear Co(II) complex of N,N,N',N'-tetrakis(2-benzimidazolylmethyl)-2-hydroxyl-1,3-diaminopropane (HL), [Co(2)L(mu(2)-Cl)](ClO(4))(2) x 3CH(3)CN x C(2)H(5)OC(2)H(5) (1), has been synthesized and its crystal structure and magnetic properties are shown. In 1, each Co(II) atom has a distorted trigonal bipyramidal geometry with a N(3)OCl donor set. The central two Co(II) atoms are bridged by one alkoxo-O atom and one Cl atom with the Co1-Co2 separation of 3.239 A. Susceptibility data of 1 indicate strong intramolecular antiferromagnetic coupling of the high-spin Co(II) atoms. In this paper, the interaction with calf thymus DNA was investigated by UV absorption and fluorescent spectroscopy. Results show the complex binds to ct-DNA with a intercalative mode. The interaction between complex 1 and pBR322 DNA has also been investigated by submarine gel electrophoresis, noticeably, the complex exhibits effective DNA cleavage activity in the absence of any external agents.

Catalytic Promiscuity in Biomimetic Systems: Catecholase-like Activity, Phosphatase-like Activity, and Hydrolytic DNA Cleavage Promoted by a New Dicopper(II) Hydroxo-Bridged Complex

Presented in this Communication are the structure, physicochemical properties, and catalytic promiscuity of a new dinuclear CuII(mu-OH)CuII complex containing a novel N,O-donor symmetric dinucleating ligand.