Electrochemical Study on the Interaction Between Neutral Red and DNA

A voltammetric study of the interaction of neutral Red(NR) with DNA at a gold electrode in a phosphate buffer solution is described. After adding DNA in an NR solution, the reduction peak current of NR decreases. The binding mechahisms of NR to DNA in different pH ranges are different. The reduction peak potential of NR in a pH 7.0 phosphate buffer solution in the presence of DNA shifts positively, indicating that the binding of NR to DNA is intercalation action, but at pH=6.0 the reduction peak potential of NR shifts negatively, indicating that the binding of NR to DNA is electrostatic action. The formed complexes are DNA-NR when [NR]/[DNA]<0.18 and DNA-3NR when [NR]/[DNA]>0.35, respectively.

Two New Compounds from Rhododendron Przewalskii Maxim

Two new ionone derivatives, rhododendrone A and rhododendronside, have been isolated from the alcoholic extract of the aerial parts of Rhododendron Przewalskii Maxim . The structures of the two compounds, (3R,6S) -3-hydroxy- α -ionone 1 and 1,1,5-trimethyl-6-(3-hydroxyl)cyclohexene-5-yl-1- β-D -pyranoglucoside 2, have been elucidated on the basis of the spectroscopic analyses.

Synthesis and Crystal Structures of the α and β Forms of Bis(salicylaldoxime)copper(Ⅱ) Complexes

Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same structure with different geometric parameters. The α form crystallizes in the P2(1)/c space group and the β form in the P1 space group. Both the crystal structures consist of centrosymmetric monomeric molecules of Cu(OC_6H_4CNOH)_2. The IR spectra are in agreement with the structural data.

Electrochemical and Spectroscopic Studies on Interaction between Complex of Copper(Ⅱ) with Schiff Base Ligand and DNA

The crystal structure of ([CuL(H_2O)_2](ClO_4)_2·2H_2O, CuL)(L=N-(5-sulfosalicylidene)-4′-bromoaniline) was determined by means of X-ray crystallography. The interaction between CuL and salmon sperm DNA in a 0.1 mol/L HOAc-NaOAc buffer solution(pH 5.10) was investigated by cyclic voltammetry and UV-Vis spectroscopy. A couple of redox peaks of CuL in the cyclic voltammograms(CV) can be seen at the glassy carbon electrode. It was found that the peak current of CuL decreased significantly with a negative shift of the peak potential in the presence of DNA compared with that in the absence of DNA. In addition, the decreased absorbance of CuL was observed with increasing the concentration of DNA; the absorption spectrum of an ethidium bromide(EB)-DNA system in the presence of CuL confirms that the binding mode of CuL to DNA is different from the intercalation of EB with DNA. All the experimental results indicate that CuL can bind to DNA by electrostatic binding and form a 1∶1 association complex with a binding constant of 2.72×10 4 L/mol.

Studies on Synthesis and Biological Activities of Novel Triazole Compounds Containing Pyrimidine or N,N-Dialkyldithiocarbamate Ring

Twelve of the title compounds were synthesized. Their structures were identified by means of IR, EA, 1H NMR and MS. The IR spectra clearly show that the absorptions in the regions of 1716-1666 cm -1 and 1505-1499 cm -1 are the characteristic absorption bands for ν C=O and ν C=N . In the 1H NMR spectra of target compounds(10a-10g), three protons of a \{\}CH-CH 2- group present three sets of quartet peaks of the protons. The preliminary bioassays showed that the synthesized compounds exhibited some activities of fungicides and plant growth regulators.

Studies on Syntheses and Biological Activities of Novel Triazole Compounds Containing Phosphorodithioate Groups

Sixteen new triazole organic phosphorus compounds were synthesized. Their structures were confirmed with IR, 1H NMR, elemental analysis and MS. The primary biological tests show that the titled compounds have the fungicidal activities, which are influenced by R groups and the substituents attached to the P atom.

Studies on Synthesis and Biological Activities of Novel Triazole compounds Containing Thiophene Groups

Fifteen new triazole compounds containing thiophene groups were synthesized and their structures were confirmed by means of 1H NMR, IR, MS spectroscopies and elemental analyses. The preliminary biological tests show that the titled compounds exhibit some activities of fungicides and plant growth regulators.

Synthesis and Crystal Structure of O-Ethyl-N- (2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate

The crystal and molecular structures of O-ethyl-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography. It crystallizes in the orthorhombic system with space group P2(1)2(1)2(1), lattice parameters a=0.90636(18) nm, b=0.94716(19) nm, c=2.1855(4) nm, V=1.8762(7) nm 3, and Z=4. All the substituents are in equatorial positions. There are four intramolecular interactions, each forming a five-membered ring. The molecules are linked by interactions to form three-dimensional framework. Atoms O6 and O8 show positional disorder.

Synthesis and Crystal Structure of 4-Salicyli deneamino-3-methyl-1,2,4-triazol-5-thione

The crystal structure of 4-salicylideneamino-3-methyl-1,2,4-triazol-5-thione 1 (C10H10N4OS, Mr = 234.28) has been determined by single-crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n with a = 12.697(3), b = 7.4072(15), c = 12.750(3) , b = 117.68(3), V = 1061.85(4) 3, Z = 4, Dc = 1.465 g/cm3, m = 0.288 mm-1 and F(000) = 488. R = 0.0584 and wR = 0.1642 for 2660 unique reflections with 2130 observed ones (I > 2s(I)). The results confirmed that the configuration of the title compound at the azomethine C=N bond is E and 1 can be assigned as the thione tautomeric form. All atoms of the title compound are essentially coplanar.

Synthesis and Crystal Structure of 5-Nitro-4-salicylidene-amino-3-methyl-1,2,4-triazol-5-thione

The crystal structure of 5-nitro-4-salicylideneamino-3-methyl-1,2,4-triazole-5-thione ([C 10 H 9N 5O 3S]·HCON(CH 3) 2, M r=352.38)(CCDC No. 216094) was determined by the single crystal X-ray diffraction method. The crystal belongs to a triclinic system, the space group is P1 with unit cell constants a= 0.6113(2) nm, b=1.0836(4) nm, c=1.3132(5) nm, α=74.523(7)°, β=117.68(3)°, γ= 79.769(7)°, V=0.8245(5) nm 3, Z=2, D c=1.419 g/cm 3, μ=0.228 mm -1 , F(000)=368, R and wR are 0.0579 and 0.1040, respectively, beasd on 3348 unique reflections of which 1925 reflections were observed[I>2σ(I)]. The results indicate that the title compound can be assigned to the thione tautomeric form rather than the thiol tautomeric form. It contains a five membered triazole ring and a phenyl ring with a dihedral angle of 4.35°. The intermolecular hydrogen bond N3_H3…S1, O1_H1…O4 can be observed.