Synthesis,Crystal Structure and DNA Binding Studies of α,α'-Bis(3,5-bismethyl-1-pyrozolyl)-carbene-acetyl-isopropenyl Hydrazine

The title compound α,α'-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopro- penyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, 1H-NMR and 13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data: triclinic, space group P1 with a = 6.9734(16), b = 10.773(3), c = 12.001(3) , α = 75.311(4), β = 82.695(4), γ = 77.143(4)o, Z = 2, V = 847.9(3) 3, Dc = 1.231 g/cm3, F(000) = 336 and μ(MoKα) = 0.082 mm-1 (λ = 0.71073 ). The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 104 M-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 104 M-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders. Keywords: α,α'-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopropenyl, preparation, crystal structure, DNA binding     

Synthesis,Crystal Structure andDNA Binding Studies of α,α′-Bis（3,5-bismethyl-1-pyrozolyl）-carbene-acetyl-isopropenyl Hydrazine

The title compound α,α′-bis（3,5-bismethyl-pyrozole-N-yl）-carbene-acetyl-isopropenyl hydrazine （C16H22N6O, Mr = 314.40） has been prepared. It was characterized by elemental analysis as well as IR, MS, ^1H-NMR and ^13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data： triclinic, space group P1^- with a = 6.9734（16）, b = 10.773（3）, c = 12.001（3）A, α = 75.311（4）, β = 82.695（4）, ）,γ = 77.143（4）°, Z = 2, V = 847.9（3）A^3, Dc = 1.231 g/cm^3, F（000） = 336 and/μ（MoKα） = 0.082 mm^-1 （λ= 0.71073A）. The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 10^4 M^-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 10^4 M^-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders.     

Binding studies of DNA with Co(Ⅲ) coordination compound

The binding of Co(bpy)2dppz3+ to calf thymus DNA was investigated by using absorption and emission spectroscopy,DNA melting techniques,cyclic voltammetry,viscosity and electro-phoresis measurements,where bpy is 2,2'-bipyridyl,dppz is dipyrido[3,2-o:2',3'-c] phenazine.The binding compound shows absorption hypochromicity,fluorescence enhancement,and increasing of DNA melting temperature and the specific viscosity.CV measurement shows the shifts in oxidation-reduction potential and change in peak current with addition of DNA.The compound is also shown to be more efficient photosensitisers for strand breaks in plasmid DNA.     

DNA cleavage mediated by water-soluble manganese corrole

The DNA nuclease-like activity of a water soluble manganese corrole 5,10,15-tris(N-methyl-4-pyridyl)- corrolatomanganese (Ⅲ)(Mn~ⅢTMPyC) has been investigated.Mn~ⅢTMPyC may bind strongly to DNA via outside groove binding mode as indicated by absorption spectra,viscosity measurements and CD spectra.Mn~ⅢTMPyC exhibited excellent catalytic activity in the DNA oxidative cleavage in the presence of hydroperoxide.     

Synthesis,Crystal Structure and Antitumor Activity of N-（4-tert-butyl-5-（4-chlorobenzyl）thiazol-2-yl）-2,6-difluorobenzamide

The title compound was synthesized by the reaction of 4-tert-butyl-5-(4-chlorobenzyl)-2-aminothiazole with 2,6-difluorobenzoic acid. The crystal structure of the title compound, C21H19ClF2N2OS, was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pbca with a = 12.6479(13), b = 13.1204(13), c = 14.1341(15), Z = 4, V = 2011.5(4)3, Mr = 420.89, Dc = 1.390 g/cm3, S = 1.023, μ = 0.326 mm-1, F(000) = 872, the final R = 0.0365 and wR = 0.0880 for 6101 observed reflections(I 2σ(I)), and R = 0.0507, wR = 0.0978 for 7779 independent reflections. X-ray crystal structure displays that the hydrogen bonding interactions observed link the molecules to form a dimeric unit. The preliminary biological test of the title compound shows good antitumor activity, with IC50 of 0.046 μmol/mL against the Hela cell line.     

DNA Binding and Oxidative Cleavage by a Water-soluble Carboxyl Manganese（Ⅲ） Corrole

The interaction of calf thymus DNA （CT DNA） and water-soluble manganese corrole, 5,10,15-tris（4-carboxyphenyl）corrolatomanganese（Ⅲ） （MnuTCPC） has been studied by absorption spectra, fluorescence spectra and CD spectra, as well as by viscosity measurements. Results revealed that this manganese corrole binds to CT DNA via an outside groove binding mode with intrinsic binding constant Ku of 4.67 × 104 Lomol L DNA cleavage activities of MnmTCPC in the presence of various oxidants were also investigated, MnmTCPC can cleave the supercoiled plas- mid pBR322 DNA to both nicked and linear form in the presence of hydrogen peroxide or tert-BuOOH, while no nuclease activity was observed by using KHSO5 as oxidant. Inhibitor tests revealed that hydroxyl radicals or singlet oxygen was not involved in MnTCPC mediated DNA oxidative cleavage. It is suggested that （oxo）manganese（V） corrole is the possibly active intermediate in this oxidative cleavage reactions.     

Spectral studies of the interaction between sanguinarine and guanosine

The interaction between sanguinarine and guanosine was investigated by using UV-vis and fluorescence spectra at pH 7.2. The binding of sanguinarine to guanosine was substantiated by the hypochromism and bathochromism in the absorption spectra and the emission quenching in fluorescence spectra. The fluorescence lifetime results, the varieties of the fluorophore absorption spectra and the decrease of the binding constant with the increasing temperature all indicate that the fluorescence quenching is static. The ratio and constant of the binding cytidine to sanguinarine are 2 and 6.44 × 10^7, respectively. The result shows that the binding of sanguinarine to guanosine is not only exothermic but also entropy-driven with △H=-8.53kJ/mol, AS = 0.12 kJ/（molK）, and AG =-44.57 kJ/mol at 298.15 K.     

CRYSTAL AND MOLECULAR STRUCTURE OF N, N-PLATINUM-DIETHYL-DICHLORIDEDI-L-ASPARTATE

This paper reports the crystal and molecular structure of title compound. 3978 three-dimensional independent reflections were collected by Syntex R3 four circle diffractometer. The crystal is monoclinic with space group P2_1, a=8.074(1), b=11.309(4), c=27.793(9), β=106.84°(2), Z=4. The molecular formula is Pt(C_8 H_(15)O_4N)_a Cl_2. The crystal structure was solved by Patterson method and refined by block matrix least squares refinement techniques. The final R factor is 0.039.The result of crystal structure analysis shows that Pt(Ⅱ) has a dsp~2 hybrid orbital and square coordination. Two C1 atoms are located oppositely to two diethyi-dichloride-di-L-aspartare. N atoms have sp~3 tetrahedral hybrid configurations and form the coordinate bonds with Pt(Ⅱ) atom using their lone pair electrons. By reason of molecular packing and due to the formation of inner hydrogen bonds in the complex molecule, the configuration of L-aspartic acid in the title complex is more twisted than that of L-and DL-aspartic acid     

Structure,Growth and Characterization of Ammonium 5-Sulfosalicylic Acid Monohydrate Crystal

Ammonium 5-sulfosalicylic acid monohydrate(NH4·C7H5O6S·H2O, ASSA) was synthesized and optical grade crystal with dimensions of 45 mm × 20 mm × 18 mm was obtained from aqueous solution by the cooling solution method. The crystal structure was confirmed by X-ray single-crystal diffraction method and the empirical composition is C7H11NO7 S with formula weight 253.23. The crystal belongs to monoclinic space group P21/c with a = 11.884(9), b = 7.306(5), c = 12.152(9) , β= 104.851(13)°, V = 1019.8(13) 3, Z = 4, Dc = 1.649 g/cm3, μ = 0.340 mm-1, F(000) = 528, the final R = 0.0307 and w R = 0.0866 for 7494 observed reflections(Ⅰ 2δ(Ⅰ)). Elemental analysis, IR and 1H-NMR spectrum were used to characterize the compound. Thermal analysis showed that one coordination water molecule was contained and dehydration temperature of ASSA crystal was 106℃. Optical transmission and fluorescence spectrum revealed that the ASSA crystal exhibited a strong absorption in ultraviolet region with the sharp absorption edge located at 340 nm and a significant blue fluorescent emission band at 442 nm.     

Crystal Structure and Bovine Serum Albumin Binding Studies of Methyl 4-(2,4-Dichlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

The title compound, methyl 4-(2,4-dichlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate(C_(20) H_(21)Cl_2NO_3, 1) was synthesized and the crystal structure was —determined by single-crystal X-ray diffraction. It crystallizes in tetragonal system, space group P421 c with a = 16.076(3), b = 16.076(3), c = 14.750(2) ?, V = 3811.8(14) ?3, Z = 8, R = 0.0377 and wR = 0.0845. The interactions between compound 1 and bovine serum albumin(BSA) were investigated using fluorescence spectroscopy. The results revealed that compound 1 can effectively quench the intrinsic fluorescence of BSA by static quenching mechanism. The thermodynamic parameters revealed that the action forces between compound 1 and BSA were mainly van der Waals forces and hydrogen bonds. According to F?rster's non-radioactive energy transfer theory, the binding distance between compound 1 and BSA had been determined. Furthermore, the synchronous fluorescence showed that compound 1 has few effects on the microenvironment and conformation of BSA in the binding process.     

Theoretical Investigations on the Structure,Density, Thermodynamic and Performance Properties of Bis（2,2-dinitropropyl） formal

Density functional method was used to investigate the IR spectrum,heat of formation and thermal stability of a new energetic material bis(2,2-dinitropropyl) formal(BDNPF).The detonation velocity and pressure were evaluated by using the Kamlet-Jacobs equations based on the theoretical density and heat of formation.The bond dissociation energies for the weakest bonds were analyzed to investigate the thermal stability of the title compound.The results show that the C(1)-N(1) bond is predicted to be the trigger bond during pyrolysis.The crystal structure obtained by molecular mechanics belongs to the P21 space group,with the lattice parameters to be Z = 2,a = 11.5254,b = 6.2168,c = 9.5000  and ρ= 1.66 g/cm3.     

Studies on the Interaction of Dinitratobis（phen） Cadmium Complex with DNA

DNA-binding properties of the dinitratobis（phen） cadmium complex [Cd（phen）2（NO3）2] （where phen = 1,10-phenanthroline） have been investigated with absorption titration, fluorescence spectroscopy, viscosity measurement, molecular modeling and density functional theory （DFT） calculations. The results indictate DNA-binding mode of the complex to be weak groove binding rather than partial intercalative interaction expected of the extended planar aromatic phen ring. In addition, the DNA cleavage study was carried out by gel electrophoresis experiment. The results showed that the complex both hardly cleaves pBR322 DNA in the absence and present ascorbate. So it is suggested that the formation of cadmium complex can decrease cadmium toxicity to some extents.     

Synthesis,Crystal Structure and Bioactivity of N-（phenethylcarbamothioyl）cyclopent-1-enecarboxamide

The compound N-(phenethylcarbamothioyl)cyclopent-1-enecarboxamide was synthesized by the reaction of cyclopent-1-enecarbonyl isothiocyanate with phenethylamine in acetone, and its structure was characterized by IR, 1H NMR and X-ray crystal structure determination. The crystal of the title compound belongs to triclinic, space group P1 with a = 6.9500(7), b = 9.4618(9), c = 11.3256(11), α = 71.522(9), β = 81.830(8), γ = 89.237(8)o, Z = 2, V = 698.80(12)3, Dc = 1.304 g/cm3, μ = 0.225 mm-1, F(000) = 292, R = 0.0413 and wR = 0.1073 for 1996 observed reflections with I 2σ(I). Intramolecular N(2)–H(2)···O(1) interactions as well as intermolecular N(2)–H(2)···O(1), N(1)–H(1)···S(1) and C(12)–H(12)···S(1) hydrogen bonds help to stabilize the crystal structure. X-ray diffraction analysis reveals that the structure of the new compound exhibits a one-dimensional infinite chain-like structure. The cytotoxicity of the compound was investigated by MTT assay. The results show that the compound is toxic to A549 tumor cell.     

Synthesis, Structure and Properties of Co(NH_2CSNHNH_2)_3Cl_3·1/2HCl

The single crystal of title compound was obtained in the solution of DMF and CH3OH under the radiation of IR lamp. The crystallographic parameters obtained are as follows: trigonal system, space group P 31C, Z=4, a=b=1.0008(2) nm, c=2. 4011 nm; final R=0. 099, Rw = 0. 092. The properties of title compound were characterized by IR, UV, EPR, XPS and CV measurements.     

Synthesis and Crystal Structure of 4-(N,N-Diphenylamino)styrene- 4′-N-methylpyridinium Iodine

The title compound 4-(N,N-diphenylamino)styrene-4′-N-methylpyridinium iodine (abbreviated to PASMPI) was synthesized by a facile condensation reaction with a high yield. The red crystal including a molecule of CHCl3 was obtained by recrystallization in chloroform/ethanol. Its crystal structure was determined by a four-circle diffractometer. The crystal data: C26H23N2ICHCl3, Mr = 609.73, orthorhombic, space group Pbca, a = 15.422(5), b = 14.042(5), c = 24.693(5) , V = 5347(3) 3, Z = 8, Dc = 1.515 g/cm3, F(000) = 2432, μ(MoKa) = 0.057 mm-1, the final R = 0.0439 and wR = 0.0772. The results reveal that the molecule is a completely reverse system. The molecular rotation from non-coplanar to coplanar may play an important role in increasing the fluorescence intensity under the condition of staining DNA.     

Syntheses,Crystal Structures and DNA-binding Properties of Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) Compounds Containing Thiazole Derivatives

Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1～3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) have been determined by single-crystal X-ray diffraction analysis, which shows that all the three complexes belong to monoclinic system with space group P21/c. Time-dependent density functional theory(TD-DFT) calculation is performed on a reference structure of compound 3. The excited electrons mainly localized at the π* of ligand 2-(2-pyridyl)benzothiazole, which will be convenient for them to bind with the DNA reacting sites. Fluorescence spectroscopy, ultraviolet(UV) spectroscopy and viscosity were used to characterize the interaction of the compounds with Calf thymus DNA(CT-DNA). The results indicate that compounds 1～3 bind to CT-DNA and have a strong interaction with DNA. The compounds can probably bind to CT-DNA via a non-intercalative mode as concluded by studying the viscosity of a DNA solution in the presence of the compounds. This combination can effectively break DNA, which speculates that these three compounds may interact with the cancer cell DNA in this binding mode, thereby damaging the cancer cells.     

SYNTHESIS AND CRYSTAL STRUCTURE OF MgCl_2(CH_3COOC_2H_5)_2

The crystal of the title compound was prepared and its structure determined by X-ray diffraction method.1672 independent reflections were collected. The crystal is orthogonal with space group P2_12_12, and a=7.353(3),b=25.111(10), c=8.631(2), Z=8. The structure was solved by using Patterson method and modified with LSM program.The final R= 0.0795. The structural features of the title compound are:Mg(Ⅱ) is octahedral and ethyl acetate is located on trans-position.Mg atoms are connected by double chloro-bridge and form polychains.     

Synthesis and Crystal Structure of 2,3,4,6-tetra-O-Acetyl-1-{4-chloro-3-[1-（4-ethoxyphenyl）-1-methylethyl]phenyl}-1-deoxy-β-D-glucopyranose

The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of monoclinic system(C31H37ClO10,Mr = 605.06),space group P21 with a = 11.882(5),b = 10.106(5),c = 13.816(6),V = 1545.9(12)3,Z = 2,Dc = 1.300 g/cm3,F(000) = 640,μ = 0.179 mm-1,the final R = 0.0430 and wR = 0.0595 for 4960 observed reflections(I > 2σ(I)).The title compound was confirmed to be a β-anomer by single-crystal X-ray diffraction and 1H NMR.The proximal benzene ring is nearly orthogonal to the glucopyranoside ring,and the two benzene rings are also almost orthogonal to each other.Four non-classical intermolecular hydrogen bonds observed in the crystal lattice help to stabilize the crystal.     

Synthesis,Crystal Structure and Interaction with DNA of a Novel Chromium（Ⅲ） Complex Containing Salicylaldehyde Semicarbazone

The novel chromium（Ⅲ） complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pbca with a = 8.9849（13）, b = 12.0475（16）, c = 34.522（5）A, V = 3736.9（9）A3, Z = 8, C16H18C1CrN6O5, Mr= 461.81, De= 1.642 g/cm^3, F（000） = 1896,A（MoKα） = 0.799 mm^-1, the final R = 0.0370 and wR = 0.0827 for 2908 observed reflections with I 〉 2σ（I）. The interaction between the chromium（Ⅲ） complex with calf thymus DNA （Ct-DNA） has been investigated by absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The results indicated that the complex was bonded to Ct-DNA through a non-classical intercalative mode.     

Synthesis, Crystal Structure and Biological Activities of N＇ - （ 4-Methoxybenzylidene ） -2- （ 1H-1, 2,4- triazol-1-yl） acetohydrazide

The title compound, N‘-( 4-methoxybenzylidene ) -2-( IH-1, 2,4-triazol-1-yl ) acetohydrazide, was synthesized and its structure was confirmed by means of IR, MS,^1H NMR and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound has a low antifungal activity.