Syntheses, Characterization, Crystal Structures and Xanthine Oxidase Inhibitory Activity of Hydrazones.

Four new fluoro-containing hydrazones were synthesized from 4-fluorobenzaldehyde with chloro- and nitro-substituted benzohydrazides. They are 3-chloro-N'-(4-fluorobenzylidene)benzohydrazide (1), 2-chloro-N'-(4-fluorobenzylidene)benzohydrazide (2), N'-(4-fluorobenzylidene)-4-nitrobenzohydrazide (3), and N'-(4-fluorobenzylidene)-3-nitrobenzohydrazide (4). The compounds have been characterized by IR and 1H NMR spectra, as well as X-ray single crystal determination. Xanthine oxidase (XO) inhibitory activity indicated that the nitro substituted compounds 3 and 4 have effective activity. Docking simulation was performed to insert the compounds into the crystal structure of xanthine oxidase at the active site to investigate the probable binding modes.

Copper(II) and Nickel(II) Complexes Derived from Isostructural Bromo- and Fluoro-Containing Bis-Schiff Bases: Syntheses, Crystal Structures and Antimicrobial Activity.

A mononuclear copper(II) complex [CuLa] (1), and three mononuclear nickel(II) complexes [NiLa] (2), [NiLa]·CH3OH (2·CH3OH) and [NiLb] (3), where La and Lb are the dianionic form of N,N'-bis(4-bromosalicylidene)-1,2-cyclohexanediamine (H2La) and N,N'-bis(4-fluorosalicylidene)-1,2-cyclohexanediamine (H2Lb), respectively, were prepared and structurally characterized by spectroscopy method and elemental analyses. The detailed structures were determined by X-ray single crystal diffraction. All the copper and nickel complexes are mononuclear compounds. The metal ions in the complexes are in square planar coordination, with the two phenolate oxygens and two imine nitrogens of the Schiff base ligands. The biological effect of the four complexes were assayed on the bacteria strains Staphylococcus aureus, Escherichia coli and Candida albicans.

Trinuclear Zinc(II) Complexes Derived from N,N'-Bis(5-bromosalicylidene)-1,2-cyclohexanediamine: Syntheses, Crystal Structures and Antimicrobial Activity.

Two new trinuclear zinc(II) complexes, [Zn3I2L2(H2O)2] (1) and [Zn3(CH3OH)(DMF)L2(NCS)2] (2), where L is the dianionic form of N,N'-bis(5-bromosalicylidene)-1,2-cyclohexanediamine (H2L), have been synthesized and characterized by elemental analyses, IR and UV spectra. Structures of the complexes were further confirmed by single crystal X-ray diffraction. Both complexes are trinuclear zinc compounds. Both compounds are solvated, with water ligand for 1 and methanol ligand for 2. The outer two Zn atoms are in square pyramidal coordination, while the inner one is in octahedral coordination. The effect of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans were evaluated, and gave interesting results.

Syntheses, Crystal Structures and Xanthine Oxidase Inhibitory Activity of Aroylhydrazones.

A series of hydrazones, (E)-N'-(4-hydroxy-3-methoxybenzylidene)-4-nitrobenzohydrazide (1), (E)-4-(dimethylamino)-N'-(4-hydroxy-3-methoxybenzylidene)benzohydrazide (2), N'-(2-hydroxy-5-methylbenzylidene)-4-nitrobenzohydrazide (3) and 2-fluoro-N'-(2-hydroxy-5-methylbenzylidene)benzohydrazide (4), were prepared and structurally characterized by elemental analysis, IR and 1H NMR spectra, and X-ray single crystal determination. The xanthine oxidase inhibitory activities of the compounds were investigated. Among the compounds, N'-(3-methoxybenzylidene)-4-nitrobenzohydrazide (1) showed the strongest activity. Docking simulations were performed to insert the compounds into the crystal structure of xanthine oxidase at the active site and to investigate the probable binding modes.

Tetranuclear Copper(II) Complexes Derived from 5-Bromo-2-((2-(2-hydroxyethylamino)ethylimino)methyl)phenol: Synthesis, Characterization, Crystal Structures and Catalytic Oxidation of Olefins.

An acetate bridged tetranuclear copper(II) complex, [Cu4L2(µ2-η1:η1-CH3COO)6(CH3OH)2] (1), and a chloride, phenolate and azide co-bridged tetranuclear copper(II) complex, [Cu4L2Cl2(µ-Cl)2(µ1,1-N3)2]2CH3OH (2), where L is the deprotonated form of the Schiff base 5-bromo-2-((2-(2-hydroxyethylamino)ethylimino)methyl)phenol (HL), have been synthesized and characterized by elemental analysis, IR and UV spectra, and single crystal X-ray diffraction. Single crystal X-ray analysis revealed that the Cu atoms in both complexes are in square pyramidal geometry. In complex 1, two [CuL] units and [Cu2(µ2-η1:η1-CH3COO)4] core are linked through two acetate ligands. In complex 2, [Cu2LCl(µ-Cl)] units are linked together by two end-on azido ligands. The Schiff base ligand coordinates to the Cu atoms through four N and O donor atoms. The molecules of both complexes are linked through hydrogen bonds to generate three dimensional networks. The catalytic property of the complexes for epoxidation reactions of some alkenes was studied using tert-butylhydroperoxide as the terminal oxidant under mild conditions in acetonitrile.

Synthesis, Biological Evaluation, and Molecular Docking Studies of Hydrazones as Novel Xanthine Oxidase Inhibitors.

A series of hydrazones, 2-cyano-N'-(4-diethylamino-2-hydroxybenzylidene)acetohydrazide (1), N'-(5-bromo-2-hydroxy-3-methoxybenzylidene)-3-chlorobenzohydrazide monohydrate (2·H2O), N'-(2-hydroxy-3-methylbenzylidene)-4-nitrobenzohydrazide (3), and N'-(2-hydroxy-3-trifluoromethoxybenzylidene)-4-nitrobenzohydrazide (4), were prepared and structurally characterized by elemental analysis, IR and 1H NMR spectra, and single crystal X-ray determination. Xanthine oxidase inhibitory activities of the compounds were studied. Among the compounds, 2-cyano-N'-(4-diethylamino-2-hydroxybenzylidene)acetohydrazide shows the most effective activity. Docking simulation was performed to insert the compounds into the crystal structure of xanthine oxidase at the active site to investigate the probable binding modes.

Synthesis, Structures, and Antibacterial Activities of Hydrazone Compounds Derived from 4-Dimethylaminobenzohydrazide.

A series of three new hydrazone compounds derived from the condensation reactions of 4-dimethylaminobenzohydrazide with 4-dimethylaminobenzaldehyde, 2-chloro-5-nitrobenzaldehyde and 3-methoxybenzaldehyde, respectively, were prepared. The compounds were characterized by elemental analysis, infrared and UV-vis spectra, HRMS, 1H NMR and 13C NMR spectra, and single crystal X-ray diffraction. Crystals of the compounds are stabilized by hydrogen bonds. The compounds were assayed for antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescence and Staphylococcus aureus) and antifungal (Aspergillus niger and Candida albicans) activities by MTT method. The results indicated that compound 2 is an effective antibacterial material.

Zinc(II) Complexes Derived from Schiff Bases: Syntheses, Structures, and Biological Activity.

Three new zinc(II) complexes, [Zn2I2(L1)2] (1), [Zn(HL2)2(NCS)2] (2), and [ZnIL3] (3), where L1 is the anionic form of 2-[(6-methylpyridin-2-ylimino)methyl]phenol (HL1), HL2 is the zwitterionic form of 2-(cyclopropyliminomethyl)-5-fluorophenol (HL2), and L3 is the anionic form of 5-bromo-2-[(3-morpholin-4-ylpropylimino)methyl]phenol (HL3), have been prepared and characterized by elemental analyses, IR, UV and NMR spectra, and single crystal X-ray crystallographic determination. Complex 1 is a dinuclear zinc complex, and complexes 2 and 3 are mononuclear zinc complexes. The Zn atoms in the complexes are in tetrahedral coordination. The effect of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were evaluated.

Synthesis, Crystal Structures and Catalytic Property of Dioxidomolybdenum(VI) Complexes with Tridentate Hydrazones.

New dioxidomolybdenum(VI) complexes with the formula [MoO2L(MeOH)], derived from N'-(5-chloro-2-hydroxy-benzylidene)-2-methylbenzohydrazide (H2L1) and N'-(3,5-dichloro-2-hydroxybenzylidene)-2-methylbenzohydrazide (H2L2) were prepared. Crystal and molecular structures of the complexes were determined by single crystal X-ray dif-fraction method. Both complexes were further characterized by elemental analysis and FT-IR spectra. Single crystal X-ray structural studies indicate that the hydrazones L1 and L2 coordinate to the MoO2 cores through the enolate oxygen, phenolate oxygen and azomethine nitrogen. The Mo atoms in both complexes are in octahedral coordination. Catalytic properties for epoxidation of styrene by the complexes using PhIO and NaOCl as oxidant have been studied.

Syntheses, X-Ray Single Crystal Structures and Biological Activities of Cobalt(III) Complexes with Reduced Schiff Base Ligands.

A new mononuclear cobalt(III) complex, [Co(HL1)2]Cl (1), derived from the reduced Schiff base 2,2'-((ethane-1,2-diylbis(azanediyl))bis(methylene))diphenol (H2L1), and a new dinuclear cobalt(III) complex, [Co2(L2)2]∆2H2O (2), derived from the reduced Schiff base 6,6'-(2-hydroxypropane-1,3-diyl)bis(azanediyl)bis(methylene)bis(2-bromo-4-chlorophenol) (H2L2), were synthesized and characterized by infrared and electronic spectroscopy, and single crystal X-ray diffraction techniques. The ligands were synthesized first, and then bound to the Co(III) centre. Compound 1 contains a mononuclear [Co(HL1)2]+ cation and a chloride anion. The cationic moiety possesses crystallographic inversion center symmetry. Compound 2 contains a dinuclear [Co2(L2)2] molecule and two water hydrate molecules. The Co atoms in the complexes are in octahedral coordination. Both complexes showed potential antimicrobial activity.

Syntheses, Crystal Structures, Antimicrobial Activity and Thermal Behavior of Copper(II) Complexes Derived from 1-Naphthylacetic Acid and Diamines.

Two copper(II) complexes, [CuL2(EA)] (1) and [Cu2L4(PA)2]·2H2O (2·2H2O), where L is 1-naphthylacetate, EA is N,N-diethylethane-1,2-diamine, PA is propane-1,3-diamine, have been prepared and characterized. Structures of the complexes have been characterized by single-cyrstal X-ray diffraction. Complex 1 is a mononuclear copper(II) compound, with the Cu atoms coordinated in square planar geometry. Complex 2·2H2O is a centrosymmetric dinuclear copper(II) compound, with the Cu atoms coordinated in square pyramidal geometry. Single crystals of the complexes are stabilized by hydrogen bonds. The effects of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans, as well as thermal behavior of the complexes were studied.

Synthesis, Crystal Structures, and Antimicrobial Activity of Zinc(II) and Manganese(II) Complexes Derived from N'-(1-(Pyridin-2-yl)Ethylidene)Isonicotinohydrazide.

Two mononuclear zinc(II) and manganese(II) compounds, [ZnL2] (1) and [MnL(HL)]ClO4 (2), where L is the monoanionic form of N'-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide (HL), and HL is the zwitterionic form of HL, have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single-crystal X-ray crystallographic determination. Compound 1 contains a neutral [ZnL2] complex molecule. Compound 2 contains a [MnL(HL)]+ complex cation and one perchlorate anion. The metal atoms in the complexes are in octahedral coordination. The hydrazone ligands coordinate to the metal atoms through the pyridine N, imine N, and enolate O atoms. The compounds were investigated for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans.

Synthesis, Characterization and Crystal Structures of Oxidovanadium(V) Complexes with Schiff Base and Pyrone Ligands and Their Antimicrobial Activity.

Two oxidovanadium(V) complexes, [VOLLa] (1) and [VOLLb] (2), where L is the dianionic form of the Schiff base ligand 2-(((2-hydroxyethyl)imino)methyl)-6-methylphenol (H2L), La and Lb are the deprotonated forms of 3-hydroxy-2-methyl-4H-pyran-4-one (HLa) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HLb), respectively, have been prepared and characterized by elemental analyses, IR, UV-Vis, 1H NMR and single-crystal X-ray crystallographic determination. The V atoms in the complexes are in octahedral coordination, with the Schiff base ligand mer-coordinated to the metal atoms through the phenolate O, imino N and hydroxyl O atoms, and with the pyrone ligands coordinated to the metal atoms through the two O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Synthesis, Crystal Structures and Antimicrobial Activity of Oxidovanadium(V) Complexes with Hydrazone and Pyrone Ligands.

A pair of oxidovanadium(V) complexes, [VOLL1] (1) and [VOLL2] (2), where L is the dianionic form of the hydrazone ligand N'-(5-chloro-2-hydroxybenzylidene)pivalohydrazide (H2L), L1 and L2 are the deprotonated forms of 3-hydroxy-2-methyl-4H-pyran-4-one (HL1; maltol) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HL2; ethyl maltol), respectively, have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single-crystal X-ray crystallographic determination. The V atoms in the complexes are in octahedral coordination, with the hydrazone ligand coordinated to the V atoms through the phenolate O, imino N and enolate O atoms, and with the pyrone ligands coordinated to the V atoms through two O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Synthesis, Crystal Structures and Catalytic Property of Dioxomolybdenum(VI) and Nickel(II) Complexes Derived from bis-Schiff Bases.

A new mononuclear dioxomolybdenum(VI) complex, [MoO2L1], and a new linear trinuclear nickel(II) complex, [NiNiL2(?1-?1:?0-OAc)(?2-?1:?1-OAc)2]·H2O, where L1 is the dianionic form of N,N'-bis(5-fluorosalicylidene)-1,3-propanediamine (H2L1), L2 is the dianionic form of N,N'-bis(5-fluoro-2-hydroxybenzylidene)-2-hydroxy-1,3-propanediamine (H2L2), have been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray determination. The Mo atom in the molybdenum complex is coordinated by four donor atoms of the Schiff base ligand, and two oxo groups, forming an octahedral coordination. In the nickel complex, there are three bridges across the Ni-Ni atom pairs, involving two phenolate O atoms of a Schiff base ligand, and an O-C-O moiety of a ?2-?1:?1-OAc group. The central Ni atom is located on an inversion center and has octahedral coordination involving four bridging O atoms from two Schiff base ligands in the equatorial plane and two O atoms from two ?2-?1:?1-OAc ligands in the axial positions. The coordination around the terminal Ni atoms is also octahedral, with two imino N and two phenolate O atoms from a Schiff base ligand defining the equatorial plane, and with two O atoms respectively from a ?1-?1:?0-OAc and a ?2-?1:?1-OAc ligands occupying the axial positions. The molybdenum complex has excellent catalytic property for sulfoxidation reactions.

Synthesis, Crystal Structures and Catalytic Oxidation of Manganese(III) Complexes Derived from Salen-Type Schiff Base N,N'-Bis(5-nitrosalicylidene)ethane-1,2-diamine.

Two mononuclear Schiff base manganese(III) complexes, [MnL(N3)(OH2)]·CH3OH (1) and [MnL(NCS)(OH2)] · H2O (2), where L is the dianionic form of N,N'-bis(5-nitrosalicylidene)ethane-1,2-diamine, have been prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy and single crystal X-ray diffraction. The Mn atom in each complex is in an octahedral coordination. Molecules of the complexes are linked through intermolecular hydrogen bonds. Catalytic properties for epoxidation of styrene by the complexes using PhIO and NaOCl as oxidant have been studied.

A Rarely Seen Phenolato and Azido-Bridged Polymeric Cadmium(II) Complex Derived from 2-Bromo-6-[(2-isopropylaminoethylimino)methyl]phenol.

A rarely seen phenolato and azido-bridged polymeric cadmium(II) complex derived from the Schiff base ligand 2-bromo-6-[(2-isopropylaminoethylimino)methyl]phenol (HL) has been prepared and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. The Schiff base ligand coordinates to the Cd atom through the NNO donor set. The Cd atom is hexa-coordinated in an octahedral geometry. Adjacent two Cd atoms are bridged by two phenolato groups generating a dimer with Cd···Cd distance of 3.475(1) Å. The dimers are further linked via azido bridges forming 2D sheets parallel to the bc plane.

Synthesis, Structures and Antimicrobial Activities of Two Cobalt(II) Complexes [Co(L1)2(OH2)2] and [Co(L2)2].

A new cobalt(II) complex, [Co(L1)2(OH2)2] (1), was prepared by the reaction of 3-bromo-5-chlorosalicylaldehyde (HL1) with cobalt nitrate in methanol. Reaction of 1 with cyclopropylamine in methanol afforded the Schiff base cobalt(II) complex, [Co(L2)2] (2), where L2 is the deprotonated form of 2-bromo-4-chloro-6-(cyclopropyliminomethyl)phenol (HL2). The complexes have been characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. The L1 ligand coordinates to the Co atom through the phenolate O and carbonyl O atoms, while the L2 ligand coordinates to the Co atom through the phenolate O and imino N atoms. The Co atom in complex 1 adopts octahedral coordination and that in complex 2 adopts tetrahedral coordination. The effect of the free ligands and the cobalt complexes on the antimicrobial activities against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Synthesis, Crystal Structure, and Catalytic Property of Dioxomolybdenum(VI) Complex Derived from 4-Bromo-N'-(4-diethylamino-2-hydroxybenzylidene) benzohydrazide.

A novel dioxomolybdenum(VI) complex, [MoO2L(MeOH)], where L is the anion of 4-bromo-N'-(4-diethylamino-2-hydroxybenzylidene)benzohydrazide, has been synthesized and characterized by physico-chemical methods and single crystal X-ray determination. In the complex the Mo atom is in octahedral coordination, with three donor atoms of the hydrazone ligand, two oxo groups, and one methanol O atom. The complex exhibits catalytic property for the sulfoxidation reactions. In the presence of the complex a 93% conversion of the sulfide to the corresponding sulfoxide was observed within 60 min and the 100% conversion was achieved after 2 h.

A novel recycling system for nano-magnetic molecular imprinting immobilised cellulases: Synergistic recovery of anthocyanin from fruit and vegetable waste.

Fruit and vegetable waste (FVW) is become a serious problem in developing countries. Enzymolysis is a potentially useful method for the treatment of FVW. In the present study, novel recycled magnetic molecular imprinting immobilised cellulases were prepared based on magnetic modified chitosan (MCTS) and Fe3O4. The properties of obtained were characterised by IR and grain-size measurements. Evaluation of a single factor affecting the loading efficiency of supports and the mixed immobilised enzymes showed better capacity than single immobilised, or free, enzymes. The immobilisation process could improve cellulase stability and repeatability of the method. Meanwhile, the kinetic parameters were also verified. The immobilised enzymes retained most of their capacity after 60days' storage while free enzymes lost it within 30days. Tests showed that the immobilised enzymes developed excellent capacity and five anthocyanins were collected.