Zheng-Yin Yang

Synthesis, characterization and biological activity of rare earth complexes of 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone isonicotinoyl hydrazone

Abstract The ligand, 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone isonicotinoyl hydrazone (H2L), was prepared by condensation of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with isoniazid. Seven complexes of rare earths with H2L have been synthesized and characterized on the basis of elemental analyses, IR, UV, 1H NMR spectra and thermal analyses. The general formula of the complexes is RE(HL)3·3.5H2O (where RE = La3+ - Gd3+). It has been discovered that the ligand and its complexes of the light rare earth metals possess antioxidative activity and inhibitory action on lipid peroxidation.

Synthesis, Characterization and Scavenger Effects on O2 − of 3d Transition Metal Complexes of Isonicotinoyl Hydrazone Derived from Isoniazid with PMBP

Abstract The 3d transition metal complexes of isonicotinoyl hydrazone derived from isoniazid with l-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) have been synthesized and characterized on the basis of elemental analyses, IR UV spectra and thermal analyses. The general formula of the complexes is ML nH2O (where M(II) = Cr, Mn, Fe, Co, Ni and Cu, n = 0, 1). It has been discovered that the complexes possess certain scavenger effects on O2 − radicals.

SYNTHESIS, CHARACTERIZATION, AND BIOLOGICAL ACTIVITY OF RARE EARTH COMPLEXES OF 1-PHENYL-3-METHYL-4-BENZOYL-5-PYRAZOLONE BENZOYLHYDRAZONE

ABSTRACT 1-Phenyl-3-methyl-4-benzyol-5-pyrazolone benzoylhydrazone (H2L) was prepared by condensation of 1-phenyl-3-methyl-4-benzyol-5-pyrazolone with benzoylhdrazine. Six rare earth complexes of H2L have been synthesized and characterized on the basis of elemental analyses, IR, UV, 1H NMR spectra and thermal analyses. The general formula of the complexes is Ln(HL)3ċ3H2O (where Ln(III) = La, Pr, Nd, Eu, Gd and Er). In addition, the suppression ratio (η r) for O2 −• radicals as well as the inhibitory ratio (η 1) for lipid peroxidation were determined by an UV spectral method. The results show that η r and η 1 of the complexes are around 39–51% and 20–39% respectively. For the ligand, η r=36% η 1=18%.

Synthesis and relaxivity of polycarboxylic hydrazone rare earth complexes——Relaxivity of α-oxo-pentanedioic acid benzoyl hydrazone Gd-complexes

Synthesis of ligand, α-oxo-pentanedioic acid benzoyl hydrazone (H2LPB), and its six rare earth (La, Pr, Nd, Sm, Gd and Er) complexes are reported. The composition and the properties of the complexes were characterized by element analysis, thermal analysis, UV, IR and1H NMR spectra. Besides, relaxivity (R1) of Gd-complex has been determined by INVREC.Au program, using inversion recovery pulse sequences, R1=8.05 mmol · L−1 · s−1. The acute toxicity of Gd-complex in animal has also been tested, and the median lethal dose (LD50) is equal to (468.2±30) mg/kg.

Synthesis, Characterization and Antioxidative Activities of the Naringenin Schiff‐Base and its Complexes with Some Rare Earth Elements

A new naringenin Schiff‐base ligand (H3L) and its four complexes, Ln (H2L)2(NO3) · 3H2O [Ln=La, Eu, Dy, and Sm], have been synthesized and characterized on the basis of elemental analyses, molar conductivities, mass spectra, 1H NMR, TG‐DTA analyses, IR spectra, UV spectra, and fluorescence spectra. In addition, the suppression ratio for O2 −· and OH·, as well as the inhibitory ratio for lipid peroxidation, were investigated by spectrophotometric methods. The results showed that the naringenin Schiff‐base and its rare earth complexes have significant antioxidative activities, and the effect of the La(III) complex is stronger than that of mannitol.

Synthesis and Relaxivity of α-Oxo-γ-Ethoxycarbonylbutanoic Acid Thiosemicarbazone Rare Earth Complexes

ABSTRACT The rare earth metal complexes of α-oxo-γ-ethoxy carbonylbutanoic acid thiosemicarbazone (HEAT) have been synthesized in the template reaction when LnCl3·nH2O was added to the system dissolved α-oxopentanedioic acid and thiosemicarbazide in anhydrous ethanol and refluxed on a water bath. Although α-oxopentanedioic acid thiosemicarbazone (H2PAT) can be synthesized in the system without LnCl3·nH2O, HEAT cannot be formed under analogous conditions. This proves that the compounds LnCl>3·nH2O have a catalytic effect on the esterification reaction. The composition and nature of the complexes are characterized by elemental analyses, thermal analyses, UV, IR, and 1H NMR spectra. In addition, the relaxivity (R1) of the Gd-complex has been determined by the INVLNC.Au program using inversion recovery pulse sequences, R1=8.10 mmol·L−1·s−1.