Xue‐Mei Li

Label-free detection of DNA hybridization based on poly(indole-5-carboxylic acid) conducting polymer

An electrochemical method to directly detect DNA hybridization was developed on the basis of a new conductive polymer, which was polymerized on the glassy carbon electrode with an indole monomer having a carboxyl group, indole-5-carboxylic acid (ICA). Hybridization with complementary, non-complementary and one-base mismatched DNA targets was studied by cyclic voltammetry (CV). Results showed a significant decrease in the current upon addition of complementary target. The change in peak current that was used as an index of sensor response was found to be linear with target concentration in the range of 3.34x10(-9) to 1.06x10(-8) M. The detection limit was 1.0 nM.

Synthesis and Biological Activities of Novel Triazole Compounds Containing 1,3-Dioxolane Rings

Thirteen new triazoles containing 1,3-dioxolane rings were synthesized and their identities confirmed by means of IR, NMR, MS, elemental analysis and X-ray crystallography. The results of preliminary biological tests show that all of these compounds possess some fungicidal and plant growth regulant activities.

Investigation of the interaction between ssDNA and 2-aminophenoxazine-3-one and development of an electrochemical DNA biosensor.

An electrochemical method was used to probe the interaction between 2-aminophenoxazine-3-one (AP) and the short DNA sequence related to the hepatitis B virus (HBV), and an electrochemical DNA biosensor was developed. The voltammetric signals of AP have been investigated at bare glassy carbon electrode (bare GCE), hybrid double-stranded DNA-modified GCE (dsDNA/GCE), and single-stranded DNA-modified GCE (ssDNA/GCE) by means of differential pulse voltammetry (DPV), and the peak currents increased with respect to the order of electrodes. The extent of hybridization was evaluated on the basis of the difference between signals of AP with a probe before and after hybridization with the complementary sequence. Control experiments with noncomplementary were performed to test the selectivity of the biosensor. With this approach, a sequence of the HBV could be quantified over the range from 3.53 x 10(-7) to 1.08 x 10(-6) M, with a linear correlation of r = 0.9963 and a detection limit of 1.00 x 10(-7) M.

Synthesis and liquid crystalline properties of novel compounds containing a 3‐fluoro‐4‐cyanophenoxy group

A series of novel compounds containing a 3‐fluoro‐4‐cyanophenoxy group were synthesized and fully characterized by IR and 1H NMR, and their mesomorphic properties were studied. Seven compounds exhibited enantiotropic nematic phases and three compounds exhibited monotropic nematic phases, as confirmed by differential scanning calorimetry and polarizing optical microscopy. Selected properties of the liquid crystalline compounds synthesized were calculated by ab initio methods at a HF/6‐31G level. The bond lengths, bond angles and dihedral angles of the fragments with the same structure change little between the compounds. All the compounds with a terminal alkoxy chain approached a planar structure.

Crystal structure and thermal chemical properties of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane

The crystal structure of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane has been determined by single crystal X-ray diffraction method. The crystal belongs to triclinic system, space group P-1 with unit cell constants a = 11.2877(9) Å, b = 11.9539(9) Å, c = 12.2365(9) Å, α = 97.2580(10)°, β = 116.2850(10)°, γ = 106.3710(10)°, V = 1358.48(18) Å3, Z = 2, Dc = 1.234 g/cm3, μ = 0.079 mm−1, F(000) = 536, R and w(R) are 0.0718 and 0.2055, respectively, for 5239 unique reflections with 3745 observed reflections (I > 2σ(I)).

4-Cyano-3-fluorophenyl (2E)-3-(3-methoxy-4-pentyloxyphenyl)acrylate

# 2006 International Union of Crystallography Printed in Great Britain – all rights reserved The two molecules in the asymmetric unit of the title compound, C22H22NO4F, differ in the orientation of the 4cyano-3-fluorobenzene ring with respect to the acrylate linkage. In one of the molecules, the pentyloxy chain has an extended conformation and in the other it is folded. The molecules are linked into a three-dimensional framework by C—H O and C—H F hydrogen bonds, and by – interactions.

Di‐μ‐adipato‐κ6O,O′:O′′;O:O′,O′′‐bis[aqua­(1,10‐phenanthroline‐κ2N,N)zinc(II)]

In the title compound, [Zn2(C6H8O4)2(C12H8N2)2(H2O)2], each Zn atom is six-coordinated in the ZnO4N2 form in a distorted tetragonal–bipyramidal geometry. The water molecules act as donors in O—H⋯O hydrogen bonds, connecting the molecules into chains. The packing is further stabilized by intermolecular C—H⋯O interactions.

Ethyl 1‐acetyl‐2′‐methyl‐2‐oxo‐4′,5′‐di­hydro‐1H‐indoline‐3‐spiro‐5′‐oxazole‐4′‐carboxyl­ate. Erratum

In the title compound, C16H16N2O5, the indoline and oxazole moieties are almost planar, while the five-membered ring in the indoline moiety is slightly distorted towards an envelope conformation. The only intramolecular C—H⋯O contact forms a six-membered ring. The crystal packing is stabilized by dipole–dipole and van der Waals forces.

Synthesis, crystal structure and electrochemical behavior of di- μ -{salicylidene-[1-( t -butyl)-5-methyl-1H-pyrazole]-formohydra-zino- κ 4 O,N,O′:O′}-nitratocopper(II)

The reaction of Cu(NO3)2 with salicylidene-[1-(t-butyl)-5-methyl-1H-pyrazole]-formohydrazine (Hsal-pfh, 1) gives a binuclear Cu(II) complex [Cu2(sal-pfh)2(NO3)2] (2). The structure of the ligand was characterized by IR, EA, 1H NMR spectroscopy. The binuclear Cu complex was determined by X-ray crystallography and thermal analysis. The two Cu(II) ions are bridged by two O atoms and each copper ion is surrounded by an asymmetric sal-pfh chromophore and a group. The coordination around each copper can be best described as a distorted square-pyramidal geometry. The electrochemical experimental results indicate that 2 can bind to DNA with good stability.

CCDC 251506: Experimental Crystal Structure Determination

Related Article: Shu-sheng Zhang, Su-juan Ye, Xue-mei Li, Shan-shan Gu, Qing Liu|2005|Chem.Res.Chin.Univ.|21|545|