E. J. Gao

Hairpin-shaped tetranuclear palladium(II) complex: synthesis, crystal structure, DNA binding and cytotoxicity activity studies.

A novel tetranuclear palladium(II) complex [Pd(4)(phen)(4) (micro-pydc)(4)].10H(2)O (phen = 1,10-phenanthroline, pydc = pyridine-3,4-dicarboxylate) has been synthesized and characterized. In the tetranuclear complex, two pairs of dipalladated [Pd(phen)] moieties are bridged together by four pydc, presenting a hairpin molecular shape. The binding of the title complex with fish sperm DNA (FS-DNA) has been investigated by UV spectrum and fluorescence spectrum. All the results indicate that the complex bind to DNA in an intercalative mode and considerating the molecular shape and size, the dipalladated phenanthroline moieties bisintercalate to the base pairs of DNA. Agarose gel electrophoresis assay demonstrates the ability of the complex to cleave the pBR322 plasmid DNA. Cytotoxic activity studies show the complex exhibited good cytotoxic activity against four different cancer cell lines.

Synthesis, characterization, interaction with DNA and cytotoxicity in vitro of novel pyridine complexes with Zn(II).

Four novel Zn(II) complexes [Zn(L(1))(bipy)(H(2)O)(2)].4H(2)O(1), [Zn(L(1))(phen)(H(2)O)(2)].4H(2)O(2), [Zn(L(2))(bipy)(H(2)O)(2)].4H(2)O(3) and [Zn(L(2))(phen)(H(2)O)(2)].4H(2)O (4), where bipy=2,2-bipyridine, phen=1,10-phenanthroline, L(1)=2,2-bipyridine 5,5-dicarboxylic acid, L(2)=2,2-bipyridine-4,4-dicarboxylic acid, have been synthesized and characterized using IR, (1)H NMR, element analysis and single-crystal X-ray diffractometry. The unit cell parameters for the title complex (1), a=7.9621(10)A, b=12.6853(17)A, c=13.3714(17)A, alpha=68.549(2) degrees , beta=79.065(2) degrees , gamma=88.723(2) degrees , V=1232.5(3)A(3), Z=15, space group,P-1(2).complex (4) a=9.5710(5)A, b=14.1140(7)A, c=19.0045(9)A, alpha=90 degrees , beta=99.9920(10) degrees , gamma=90 degrees , V=2528.3(2)A(3), Z=32, space group, P121/n 1(14). The binding of the complexes with fish sperm DNA (FS-DNA) was investigated by electronic absorption spectra and fluorescence spectroscopy, showing that the complexes have the ability of interaction with DNA of intercalative mode. The intrinsic binding constant K of the complexes with FS-DNA is 0.37 x 10(5)M(-1) (1) 0.73 x 10(5)M(-1) (2), 0.98 x 10(5)M(-1) (3), and 1.05 x 10(5)M(-1) (4). The results indicate that the four complexes bound to DNA with different binding affinity, in the order complex 4>3>2>1. Gel electrophoresis assay demonstrates the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic activity of the complexes was tested against four different cancer cell lines. The four complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate.

Zigzag-shaped supramolecular networks formed via hydrogen bonding. Crystal structures, DNA binding, and cytotoxic activity of a new palladium(II) complex

A single-ligand complex Pd(II)-L-aspartic acid was synthesized and characterized by elemental ana-lysis and IR spectra. The crystal structure of the complex was determined by single crystal X-ray diffraction (crystallizing in orthorhombic crystal system, space group P212121 with unit cell parameters a = 5.3145(11) Å, b = 9.6294(19) Å, c = 22.233(4) Å, and Z = 4). The Pd atom was four-coordinated with N(1), N(2), O(4), and O(5) from two L-aspartic ligands and formed a slightly distorted parallelogram geometry. 2D “zigzag” shaped supramolecular networks are constructed via hydrogen bonding. The binding of the title complex with fish sperm DNA (FS-DNA) has been investigated by absorption and fluorescence spectra and the results indicate that the complex bind to FS-DNA in an intercalative mode. Gel electrophoresis shows the cleavage of both supercoiled and circular pBR322 DNA to form a small molecular fragment under the action of the title complex. The cytotoxicity assay proves that the complex has strong anticancer activity to human cervix epitheloid carcinoma cell lines (HeLa).

Synthesis and crystal structure of complex [Mn(Imdc)2(H2O)2] · 2H2O and its interaction with DNA

Under hydrothermal conditions, the complex [Mn(lmdc)2(H2O)2] · 2H2O (I) was synthesized and characterized by elemental analysis and IR spectrum (HImdc = 4,5-imidazofedicarboxylic acid). The crystal structure of I was determined by single-crystal X-ray diffraction (crystallizing in the monoclinic crystal system, P2/c space group, a = 11.000(2), b = 7.1281(14), c = 12.696(3) Å, β = 122.45(3), Z = 2. In I, the Mn2+ ion was chelated by two Imdc with one of their nitrogen atoms and a carboxylic oxygen atom, while two water molecules occupy the axial position of the Mn atom forming a distorted octahedral geometry. Three-dimensional structure of I was formed by intermolecular hydrogen bonds. UV-Vis and fluorescence spectra of I interacting with DNA show that insertion is the main binding mode between I and fish sperm DNA. Gel electrophoresis shows that I cleaves both supercoiled and circular pBR322 DNA to form a small molecular fragment.

Four Ln(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate ligand: Synthesis, crystal structure, and luminescence

Four Ln(III) coordination polymers, [La2(HBidc)3(H2O)]n (I), [Pr2(HBidc)3(H2O)]n (II), [Sm2(HBidc)3(H2O)]n (III), and [Gd2(HBidc)3(H2O)]n (IV), were synthesized hydrothermally by treating Ln(NO3)3 · 6H2O, NaOH, and H3Bidc (H3Bidc = 1H-benzimidazole-5,6-dicarboxylic acid) at 180°C and characterized by elemental analysis, IR spectra, and single-crystal X-ray structure analyses. Complexes I–IV are isostructural, and each complex contains two crystallographically independent Ln(III), one is seven-coordinated, while the other is eight-coordinated. X-ray crystallography reveals that the complex consists of 3D frameworks with the (34·44·52·66·710·8·9)(3·4·5)(3·4·5) topology. Furthermore, the photoluminescence properties of III has been studied.

Synthesis and crystal structure of a Cu(II) complex Cu2(Endc)2(Bipy)2 and its photoluminescence properties

AbstractA novel Cu(II) complex Cu2(Endc)2(Bipy)2 has been synthesized by the reaction of Cu(NO3)2 · 3H2O, Endc (endo-norbornene-cis-5,6-dicarboxylic acid), and Bipy (2,2-bipyridine) at room temperature. Elemental analysis, IR spectra, and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. Crystal data for this complex: triclinic, P

A novel Mn(II) complex with 3-(2,5-dicarboxyl)-5-carboxylpyridine: Synthesis, crystal structure, and interaction with DNA

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Synsthesis, crystal structure, photoluminescence, DNA cleavage, and cytotoxicity in vitro of the binuclear Ce(III) complex with quinaldic acid

with a = 9.0373(10), b = 10.1637(11), c = 10.5574(12) Å, α = 65.78(1)°, β = 72.32(2)°, β = 73.23(2)°, Z = 1, V = 827.46(16) Å3, ρc = 2.160 g/cm3, F(000) = 410.0, R = 0.0483 and wR = 0.0958 independent reflections for 4468 observed ones (I > 2 σ(I)).The Cu2+ ion is coordinated by two nitrogen atoms from the Bipy molecule and three oxygen atoms from two Endc, giving a distorted squarepyramidal coordination geometry. Two neighboring Cu2+ ions are bridged by a pair of bimonodentate carboxyl groups of different Endc acids, giving a centrosymmetrical binuclear structure which a Cu…Cu distance of 3.2946 Å. The photoluminescence properties of the complex were studied at room temperature. The complex displays an obvious photoluminescent emission upon excitation at 390 nm in the solid state.