Xiao-Shan Cheng

Synthesis, biological evaluation, and molecular docking studies of 2,5-substituted-1,4-benzoquinone as novel urease inhibitors.

A series of 2,5-substituted-1,4-benzoquinone (1-6) were prepared and structurally characterized by elemental analysis, IR spectra, (1)H and (13)C NMR spectra, and single crystal X-ray determination. The urease inhibitory activities of the compounds against H. pylori urease were studied. Among the compounds, 2,5-bis(2-morpholin-4-ylethylamino)-[1,4]benzoquinone (2) shows the most effective activity with IC(50) value of 27.30 ± 2.17 μM. Docking simulation was performed to insert compound 2 into the crystal structure of H. pylori urease at the active site to determine the probable binding mode. As a result, compound 2 may be used as a potential urease inhibitor.

Synthesis, structure, and urease inhibitory activities of three binuclear copper(II) complexes with protocatechuic acid derivative

Three Cu(II) complexes, [CuII2(L1)4(L2)2] (1), [CuII2(L1)4(H2O)2]·HL (2), and [CuII2(L1)3(L3)2]ClO4 (3), with a ligand derived from protocatechuic acid (HL1 = C9H8O4=2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylic acid, L2 = C7H9N=o-toluidine, L3 = C6H16N2=N,N-diethylethylenediamine) were synthesized and characterized by C, H, and N elemental analysis and single-crystal X-ray diffraction, which revealed that the three complexes have similar binuclear structures. Complexes 1 and 3 crystallized in triclinic space group P-1 and 2 in orthorhombic space group P212121. The urease inhibitory activities of the three complexes were tested. All three complexes showed strong inhibitory activity against jack bean urease with an IC50 value of 6.8, 5.5, and 3.5 μM compared with the acetohydroxamic acid (IC50 = 7.5 μM), which was a positive control. Graphical Abstract

Azido and Thiocyanato-Bridged Polymeric Copper(II) Complexes [CuL(μ1,3-N3)]n·2nH2O and [CuL(μ1,3-NCS)]n: Synthesis and Structures

A new azido-bridged polymeric copper(II) complex, [CuL(μ1,3-N3)]n·2nH2O (1), and a new thiocyanato-bridged polymeric copper(II) complex, [CuL(μ1,3-NCS)]n (2) (L = 4-methoxy-2-[(2-morpholin-4-ylethylimino)methyl]phenolate), have been prepared and structurally characterized by elemental analysis, IR spectra, and single-crystal X-ray determination. Each Cu atom in the complexes is coordinated by three donor atoms of Schiff bases and by two atoms of the pseudohalide ligands, forming a square pyramidal geometry. Azide and thiocyanate anions are preferred bridging groups for the construction of polymeric copper complexes with Schiff bases.

Synthesis, structures, and insulin-like activity of oxidovanadium(V) complexes derived from 2-chloro-N′-(3-ethoxy-2-hydroxybenzylidene)benzohydrazide

Abstract Three new oxidovanadium(V) complexes, [VOLL′] (L = 2-chloro-N′-(3-ethoxy-2hydroxybenzylidene)benzohydrazide, L′ = acetohydroxamate for 1, methylmaltolate for 2, and ethylmaltolate for 3), have been prepared. The complexes have been characterized by physicochemical methods and single-crystal X-ray determination. Vanadium in each complex is coordinated by the NOO donor set of L, the OO donor set of L′, and one oxido, forming octahedral coordination. The complexes were administered intragastrically to both normal and alloxan-diabetic mice for two weeks. The biological activities show that the complexes at doses of 10.0 and 20.0 mg V·kg−1 can significantly decrease the blood glucose level in alloxan-diabetic mice, but the blood glucose level in the treated normal mice was not altered.

Synthesis and Crystal Structure of a μ-Oxido-Bridged Dinuclear Iron(III) Complex Derived From 3, 5-Dichlorosalicylaldehyde and 4-(2-Aminoethyl)morpholine

A μ-oxido-bridged dinuclear iron(III) complex, [Fe2O(L1)2(L2)2], where L1 and L2 are the deprotonated forms of 2,4-dichloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol and 3,5-dichlorosalicylaldehyde, respectively, has been prepared and characterized by elemental analysis, infrared spectrum, and single-crystal X-ray determination. The complex crystallizes in the triclinic space group P, with unit cell dimensions a = 10.670(1) Å, b = 11.585(1) Å, c = 19.748(2) Å, α = 86.766(2)°, β = 85.038(2)°, γ = 73.973(2)°, V = 2336.1(4) Å3, Z = 2, GOOF = 1.019, R1 = 0.0422, and wR2 = 0.1024. Structural analysis shows that the iron atoms in the complex are hexacoordinate with a normal Fe-O-Fe bridging angle of 150.84(13)°. Each Fe atom is coordinated by the NNO donor atoms of L1, OO donor atoms of L2, and one bridging O atom. The Fe· · ·Fe distance is 3.467(2) Å.

Syntheses, characterization, and urease inhibition of oxidovanadium(V) complexes with tridentate hydrazone and bidentate benzohydroxamate ligands

New oxidovanadium(V) complexes, [VOL1(bzh))]·H2O (1) and [VOL2(bzh))] (2), were prepared by the reaction of [VO(acac)2] (where acac = acetylacetonate) and benzohydroxamic acid (Hbzh) with N′-(5-bromo-2-hydroxybenzylidene)-3-methylbenzohydrazide (H2L1) and N′-(5-bromo-2-hydroxybenzylidene)-4-methylbenzohydrazide (H2L2), respectively, in methanol. Structures of the complexes were determined by elemental analysis, infrared and UV–vis spectra. Single crystal structures of the complexes were determined by X-ray diffraction. Vanadiums have octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied. Graphical Abstract

Syntheses, Characterization, and Crystal Structures of Bromido-Coordinated Zinc(II) Complexes With Multidentate Schiff Bases

A new dinuclear bromido-coordinated Schiff base zinc(II) complex, [Zn2Br2L1(MeOH)]·MeOH (1), and a new mononuclear bromido-coordinated Schiff base zinc(II) complex, [ZnBr2L2] (2), where L1 is the dianionic form of N,N’-bis(5-fluoro-2-hydroxybenzylidene)propane-1,3-diamine (H2L1), and L2 is the zwitterionic form of 2-[(3-dimethylammoniopropylimino)methyl]-4-fluorophenol, have been preprared and characterized mainly by single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 10.0876(9) Å, b = 8.9549(8) Å, c = 26.586(2) Å, β = 95.134(2)º, V = 2391.9(4) Ǻ3, Z = 4, R1 = 0.0547, and wR2 = 0.1025. Complex 2 crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 7.359(1) Å, b = 13.798(2) Å, c = 17.676(2) Å, β = 114.602(2)º, V = 1631.8(4) Ǻ3, Z = 4, R1 = 0.0877, and wR2 = 0.2197. The inner Zn atom in 1 is five-coordinated in a square pyramidal geometry. The outer Zn atom in 1 and the Zn atom in 2 are four-coordinated in tetrahedral geometry. The crystals of the complexes are stabilized by intermolecular hydrogen bonds.

Syntheses, Crystal Structures, and Characterization of Copper(II) and Zinc(II) Complexes Derived from N,N-Dimethylethane-1,2-diamine and Phenylacetic Acid Derivatives

A new copper(II) complex, [Cu(AA)(EDA)2] (1), and a new zinc(II) complex, [Zn(PA)2(EDA)] (2), where AA is 1-naphthylacetate, PA is 4-nitrophenylacetate, and EDA is N,N-dimethylethane-1,2-diamine, have been prepared and characterized. Structures of the complexes have been characterized by single-crystal X-ray diffraction. Complex 1 crystallizes as monoclinic space group P21/n, with unit cell dimensions a = 7.3327(4) Å, b = 24.031(1) Å, c = 13.9031(7) Å, β = 91.803(2)°, V = 2448.7(2) Å3, Z = 4, R1 = 0.0487, wR2 = 0.1199, S = 1.053. Complex 2 crystallizes as monoclinic space group P21/c, with unit cell dimensions a = 24.693(4) Å, b = 12.023(2) Å, c = 7.524(1) Å, β = 89.95(3)°, V = 2233.8(6) Å3, Z = 4, R1 = 0.0696, wR2 = 0.1845, S = 0.999. Complex 1 is a mononuclear copper(II) species, with the Cu atom coordinated in a square pyramidal geometry. Complex 2 is a mononuclear zinc complex, with the Zn atom coordinated in a tetrahedral geometry. Single crystals of the complexes are stabilized by hydrogen bonds and π…π interactions.

Synthesis, Characterization, and Crystal Structures of Nickel Complexes Derived from N,N′-Bis(3,5-dichlorosalicylidene)-1,3-pentanediamine and N,N′-Bis(3-methylsalicylidene)-1,2-ethanediamine

Two new mononuclear Schiff base nickel(II) complexes, [Ni(ClSal)] (1) and [Ni(MeSal)] (2) (H2ClSal = N,N′-bis(3,5-dichlorosalicylidene)-1,3-pentanediamine; H2MeSal = N,N′-bis(3-methylsalicylidene)-1,2-ethanediamine), have been synthesized and characterized by elemental analyses, infrared spectra, and single-crystal X-ray diffraction. Complex 1 crystallizes in the orthorhombic space group P212121, with unit cell dimensions a = 9.788(1) Å, b = 10.206(1) Å, c = 20.458(2) Å, V = 2043.7(4) Å3, Z = 4, R 1 = 0.0814, and wR 2 = 0.1689. Complex 2 crystallizes in the monoclinic space group P21/n, with unit cell dimensions a = 11.6353(5) Å, b = 11.8807(6) Å, c = 12.8241(6) Å, β = 115.213(1)°, V = 1603.9(1) Å3, Z = 4, R 1 = 0.0243, and wR 2 = 0.0675. The Ni atoms in the complexes are four-coordinated in square planar geometry by the N2O2 donor set of the ligands.

Syntheses and Structures of a Pair of Isologous Complexes: ZnLCl2 and ZnLBr2

A pair of mononuclear Schiff base zinc(II) complexes, [ZnLCl2] (1) and [ZnLBr2] (2), have been prepared by the reaction of equimolar quantities of a new Schiff base ligand 2-[(2-dimethylammonioethylimino)methyl]-4-methylphenolate with ZnCl2 and ZnBr2, respectively, in methanol. The structures of the complexes have been characterized by single-crystal X-ray diffraction. Complex 1 crystallizes as orthorhombic space group P212121, with unit cell dimensions a = 7.518(1) Å, b = 13.518(2) Å, c = 14.766(2) Å, V = 1500.7(3) Å3, Z = 4, R 1 = 0.0301, wR 2 = 0.0780, S = 1.028. Complex 2 crystallizes as orthorhombic space group P212121, with unit cell dimensions a = 7.731(1) Å, b = 13.761(1) Å, c = 14.705(1) Å, V = 1564.4(1) Å3, Z = 4, R 1 = 0.0230, wR 2 = 0.0488, S = 1.031. The Zn atom in each of the complexes is four-coordinated in a tetrahedral geometry by the phenolate O and imine N atoms of the Schiff base ligand, and two halide anions. Single crystals of the complexes are stabilized by hydrogen bonds.