Showing papers on "Hydrazone published in 2011"
TL;DR: Assay on the cytotoxicity of Co, Ni and Cu hydrazone complexes against HeLa tumor cells and NIH 3T3 normal cells revealed that the complexes are toxic only against tumor cells but not to normal cells.
271 citations
TL;DR: The effect of complexes 5-8 to arrest the growth of HeLa and Hep-2 tumour cell lines has been studied along with the cell viability against the non-cancerous NIH 3T3 cells under in vitro conditions.
Abstract: Four new bivalent nickel hydrazone complexes have been synthesised from the reactions of [NiCl2(PPh3)2] with H2L {L = dianion of the hydrazones derived from the condensation of salicylaldehyde or o-hydroxy acetophenone with p-toluic acid hydrazide (H2L1) (1), (H2L2) (2) and o-hydroxy acetophenone or o-hydroxy naphthaldehyde with benzhydrazide (H2L3) (3) and (H2L4) (4)} and formulated as [Ni(L1)(PPh3)] (5), [Ni(L2)(PPh3)] (6), [Ni(L3)(PPh3)] (7) and [Ni(L4)(PPh3)] (8). Structural characterization of complexes 5–8 were accomplished by using various physico-chemical techniques. In order to study the influence of substitution in the ligand and its planarity on the biological activity of complexes 5–8 containing them, suitable hydrazone ligands 1–4 have been selected in this study. Single crystal diffraction data of complexes 5, 7 and 8 proved the geometry of the complexes to be distorted square planar with a 1 : 1 ratio between the metal ion and the coordinated hydrazones. To provide more insight on the mode of action of complexes 5–8 under biological conditions, additional experiments involving their interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) were monitored by UV-visible and fluorescence titrations respectively. Further, the ligands 1–4 and corresponding nickel(II) chelates 5–8 have been tested for their scavenging effect towards OH and O2− radicals. The effect of complexes 5–8 to arrest the growth of HeLa and Hep-2 tumour cell lines has been studied along with the cell viability against the non-cancerous NIH 3T3 cells under in vitro conditions.
152 citations
TL;DR: Two series of five membered heterocyclic bis(1,3,4-oxadiazole) derivatives 2-a-h and 3,5-bis(substituted)pyrazoles, isoxazoles, 4(a-c) were synthesized via oxidative cyclization of some diaroylhydrazones using chloramine-T and cyclocondensation reaction with hydrazine hydrate and hydroxylamine hydrochloride.
114 citations
TL;DR: Claisen condensation of 4-acetamide pyrazolone 2 with diethyl oxalate have been utility to afford new 4-oxaloacetyl antipyrine 3, which upon hydrazinolysis of the ester function to obtain the acetohydrazide derivative 18 which used as starting material to synthesize 1,2,4-triazol 19 and hydrazone 20 derivatives.
81 citations
TL;DR: The Schiff base hydrazone ligand HL was prepared by the condensation reaction of 7-chloro-4-quinoline with o-hydroxyacetophenone and its metal complexes were characterized by elemental analyses, IR, NMR, Mass, and UV-Visible spectra.
Abstract: The Schiff base hydrazone ligand HL was prepared by the condensation reaction of 7-chloro-4-quinoline with o-hydroxyacetophenone. The ligand behaves either as monobasic bidentate or dibasic tridentate and contain ONN coordination sites. This was accounted for be the presence in the ligand of a phenolic azomethine and imine groups. It reacts with Cu(II), Ni(II), Co(II), Mn(II), UO(2) (VI) and Fe(II) to form either mono- or binuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, NMR, Mass, and UV-Visible spectra. The magnetic moments and electrical conductance of the complexes were also determined. The Co(II), Ni(II) and UO(2) (VI) complexes are mononuclear and coordinated to NO sites of two ligand molecules. The Cu(II) complex has a square-planar geometry distorted towards tetrahedral, the Ni(II) complex is octahedral while the UO(2) (VI) complex has its favoured heptacoordination. The Co(II), Mn(II) complexes and also other Ni(II) and Fe(III) complexes, which were obtained in the presence of Li(OH) as deprotonating agent, are binuclear and coordinated via the NNNO sites of two ligand molecules. All the binuclear complexes have octahedral geometries and their magnetic moments are quite low compared to the calculated value for two metal ions complexes and thus antiferromagnetic interactions between the two adjacent metal ions. The ligand HL and metal complexes were tested against a strain of Gram +ve bacteria (Staphylococcus aureus), Gram -ve bacteria (Escherichia coli), and fungi (Candida albicans). The tested compounds exhibited high antibacterial activities.
78 citations
TL;DR: UV/Vis spectral studies show both tautomers to be kinetically stable (inert), that is, with no apparent tautomerization, in acetonitrile solution.
Abstract: The in situ formed hydrazone Schiff base ligand (E)-N′-(2-hydroxy-3-methoxybenzylidene)benzoylhydrazone (H2L1) reacts with copper(II) acetate in ethanol in the presence of pyridine-4-carboxylic acid (isonicotinic acid, HL2) to green-[Cu(HL1)(L2)]·H2O·C2H5OH (1) and brown-[Cu(L1)(HL2)] (2) complexes which crystallize as concomitant tautomers where either the mono-anion (HL1)− or di-anion (L1)2− of the Schiff base and simultaneously the pyridine-carboxylate (L2)− or the acid (HL2) (both through the pyridine nitrogen atom) function as ligands. The square-planar molecular copper(II) complexes differ in only a localized proton position either on the amide nitrogen of the hydrazone Schiff base in 1 or on the carboxyl group of the isonicotin ligand in 2. The proportion of the tautomeric forms in the crystalline solid-state can be controlled over a wide range from 1:2 = 95 : 5 to ∼2 : 98 by increasing the solution concentration. UV/Vis spectral studies show both tautomers to be kinetically stable (inert), that is, with no apparent tautomerization, in acetonitrile solution. The UB3LYP/6-31+G* level optimized structures of the two complexes are in close agreement with experimental findings. The solid-state structures feature 1D hydrogen-bonded chain from charge-assisted O(−)⋯H–N and O–H⋯(−)N hydrogen bonding in 1 and 2, respectively. In 1pyridine-4-carboxylate also assumes a metal-bridging action by coordinating a weakly bound carboxylate group as a fifth ligand to a Cu axial site. Neighboring chains in 1 and 2 are connected by strong π-stacking interactions involving also the five- and six-membered, presumably metalloaromatic Cu-chelate rings.
63 citations
TL;DR: In this article, the catalytic potential of the complexes has been tested for the oxidation of alkene, alkane and aromatic hydrocarbons using H2O2 as the terminal oxidant.
58 citations
TL;DR: Three different ONO donor acetyl hydrazone Schiff bases have been synthesized from the condensation of acetic hydrazide with three different carbonyl compounds and all complexes are proved to be efficient catalysts for the epoxidation of alkenes by NaOCl under phase transfer condition.
Abstract: Three different ONO donor acetyl hydrazone Schiff bases have been synthesized from the condensation of acetic hydrazide with three different carbonyl compounds: salicylaldehyde (HL1), 2-hydroxyacetophenone (HL2), and 2, 3-dihydroxybenzaldehyde (HL3). These tridentate ligands are reacted with Ni(OOCCF3)2·xH2O to yield three new Ni(II) complexes having distorted octahedral geometry at each Ni center: [Ni(L1)(OOCCF3)(CH3OH)]2 (1), [Ni(L2)(OOCCF3)(H2O)]2 (2), and [Ni(L3)(L3H)](OOCCF3)(H2O)1.65(CH3OH)0.35 (3). The ligands and the complexes have been characterized by elemental analysis and IR and UV–vis spectroscopy, and the structures of the complexes have been established by single crystal X-ray diffraction (XRD) study. 1 and 2 are centrosymmetric dinuclear complexes and are structural isomers whereas 3 is a bis chelated cationic monomer coordinated by one neutral and one monoanionic ligand. O–H···O hydrogen bonds in 3 lead to the formation of a dimer. Slight steric and electronic modifications in the ligand ...
56 citations
TL;DR: In this article, the structure and properties of bidentate hydrazone ligands were confirmed by spectral and single crystal X-ray diffraction studies, and they showed significant binding towards calf thymus DNA (CT-DNA) via groove binding mode with binding constants in the magnitude 10 4 −10 5 ǫ −1.
52 citations
TL;DR: In this paper, the synthesis of a family of macrocyclic hydrazone-based anion receptors is described. But the authors focus on the conformation of the macrocycles, particularly with reference to the formation of a helical intramolecularly hydrogen-bonded structure.
Abstract: We report the synthesis of a family of new macrocyclic hydrazone-based anion receptors. Formed from the reaction between isophthalaldehyde and a helical amino acid-disubstituted ferrocene dihydrazide, these macrocycles contain from one to eight ferrocene moieties. The isolation of the four smallest of the macrocycles and their characterisation by UV-Vis, CD and NMR spectroscopy is described. The conformation of the macrocycles is explored, particularly with reference to the formation of a helical intramolecularly hydrogen-bonded structure. An investigation of the use of these macrocycles as anion-receptors shows that they are all effective hosts; the larger macrocycles show the highest affinities for anions. Studies using NMR spectroscopy suggest that the anion-recognition results primarily from the formation of multiple hydrogen bonds between the anions and the electropositive N–H protons of the acylhydrazones.
51 citations
TL;DR: 4-aminophenylalanine is nearly as effective as aniline in catalyzing hydrazone formation between the reactive amino acid 3-formyltyrosine and hydrazine-containing fluorophores, both free in solution and incorporated into the protein tubulin.
TL;DR: In this paper, an azocoupling of diazonium salt of 2-hydroxyaniline with 1-phenylbutane-1,3-dione (H2L) was presented.
TL;DR: All compounds showed levels of inhibition of zymosan-induced peritonitis comparable or superior to indomethacin, indicating an expressive anti-inflammatory profile.
Abstract: Salicylaldehyde 2-chlorobenzoyl hydrazone (H(2)LASSBio-466), salicylaldehyde 4-chlorobenzoyl hydrazone (H(2)LASSBio-1064) and their complexes [Zn(LASSBio-466)H(2)O](2) (1) and [Zn(HLASSBio-1064)Cl](2) (2) were evaluated in animal models of peripheral and central nociception, and acute inflammation. All studied compounds significantly inhibited acetic acid-induced writhing response. Upon coordination the anti-nociceptive activity was favored in the complex 1. H(2)LASSBio-466 inhibited only the first phase of the formalin test, while 1 was active in the second phase, like indomethacin, indicating its ability to inhibit nociception associated with the inflammatory response. Hence coordination to zinc(II) altered the pharmacological profile of H(2)LASSBio-466. H(2)LASSBio-1064 inhibited both phases but this effect was not improved by coordination. The studied compounds did not increase the latency of response in the hot plate model, indicating their lack of central anti-nociceptive activity. All compounds showed levels of inhibition of zymosan-induced peritonitis comparable or superior to indomethacin, indicating an expressive anti-inflammatory profile.
TL;DR: 2-(6,8-Dibromo-2-methylquinazolin-4-yloxy)-acetohydrazide was prepared by the reaction of formamide with formamide to afford quinazolinone 2 and alkylation with ethyl chloroacetate to give the ester.
Abstract: 2-(6,8-Dibromo-2-methylquinazolin-4-yloxy)-acetohydrazide (4) was prepared by the reaction of 6,8-dibromo-2-methylbenzo-[d][1,3]oxazin-4-one with formamide to afford quinazolinone 2, followed by alkylation with ethyl chloroacetate to give the ester 3. Treatment of ester 3 with hydrazine hydrate and benzaldehyde afforded 4 and styryl quinazoline 5. The hydrazide was reacted with triethyl orthoformate, acetylacetone and ethyl acetoacetate and benzaldehyde derivatives to afford the corresponding pyrazoles 6, 7, 9 and hydrazone derivatives 10a-c. Cyclization of hydrazones 10a-c with thioglycolic acid afforded the thiazole derivatives 11a-c. Reaction of the hydrazide with isothiocyanate derivatives afforded hydrazinecarbothioamide derivatives 12a-c, which cyclized to triazole-3-thiols and thiadiazoles 13a-c and 14a-c, respectively. Fusion of the hydrazide with phthalimide afforded the annelated compound 1,2,4-triazolo[3,4-a]isoindol-5-one (15). The newly synthesized compounds were characterized by their spectral (IR, 1H-, 13C-NMR) data. Selected compounds were screened for analgesic activity.
TL;DR: Combining the rheology data with dynamic headspace analysis of fragrance evaporation suggested that reversible hydrazone formation of some carbonyl compounds influences the release of volatiles, whereas the absolute stability of the gel seemed to have no influence on theEvaporation rates.
Abstract: In the presence of alkali metal cations, guanosine-5′-hydrazide (1) forms stable supramolecular hydrogels by selective self-assembly into a G-quartet structure. Besides being physically trapped inside the gel structure, biologically active aldehydes or ketones can also reversibly react with the free hydrazide functions at the periphery of the G-quartet to form acylhydrazones. This particularity makes the hydrogels interesting as delivery systems for the slow release of bioactive carbonyl derivatives. Hydrogels formed from 1 were found to be significantly more stable than those obtained from guanosine. Both physical inclusion of bioactive volatiles and reversible hydrazone formation could be demonstrated by indirect methods. Gel stabilities were measured by oscillating disk rheology measurements, which showed that thermodynamic equilibration of the gel is slow and requires several cooling and heating cycles. Furthermore, combining the rheology data with dynamic headspace analysis of fragrance evaporation suggested that reversible hydrazone formation of some carbonyl compounds influences the release of volatiles, whereas the absolute stability of the gel seemed to have no influence on the evaporation rates.
TL;DR: The biological activity of compounds 6a, 6d, 11, 12, and 15 was evaluated as inhibitor of growth in a human liver carcinoma cell line and doxorubicine was used for comparison.
TL;DR: Three silicon centered spirocyclic compounds 1-3, possessing silicon fused six- and five-membered rings have been prepared by the reaction of NHSi with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine in a 1:1 ratio.
Abstract: Three silicon centered spirocyclic compounds 1−3, possessing silicon fused six- and five-membered rings have been prepared by the reaction of NHSi (L) [L = CH{(C=CH2)(CMe)(2,6-iPr2C6H3N)2}Si] with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine, respectively, in a 1:1 ratio. The three spirocyclic compounds (1− 3) were obtained by three different pathways. The reaction of L with benzoylpyridine leads to the activation of the pyridine ring, and dearomatization occurred. Treatment of diisopropyl azodicarboxylate with L favors a [1 + 4]- rather than a [1 + 2]-cycloaddition product, and the azo compound was converted to hydrazone derivative. Finally the reaction of 1,2-diphenylhydrazine and L results in the elimination of hydrogen by activating one of the C−H bonds present in the phenyl ring. All three complexes 1− 3 were characterized by single crystal X-ray structural analysis, NMR spectroscopy, EI-MS spectrometry, and elemental analysis. In addition the optimized structures of proba...
TL;DR: Hydrazone derivatives of vanillin are found to possess anti-bacterial activities by paper disc diffusion method against Pseudomonas aeruginosa and Staphylococcus aureus bacterial strains.
Abstract: Hydrazone derivatives of vanillin are found to possess anti-bacterial activities. Based on higher bio-activity of hydrazones, new hydrazone derivatives were synthesized from Piperdine-4-carboxylicacid methyl ester (1). The compounds 1-pyrimidine-2-yl piperidine-4-carboxylicacid(4-hydroxy-3-methoxy benzylidine)-hy- drazide (10), 1-pyrimidine-2-yl piperidine-4-carboxylicacid (3,4-dimethoxy benzylidine) hydrazide (11), 1-pyrimidine-2-yl piperidine-4-carboxylicacid(4-butoxy-3-methoxy benzylidine)-hydrazide (12), 1-pyr- imidine-2-yl piperidine-4-carboxylicacid(3-methoxy-4(2-methoxy ethoxy) benzylidine)-hydrazide (13) were synthesized, purified and characterized by 1HNMR, 13CNMR, LCMS, FT-IR and HPLC techniques. The synthesized hydrazone derivatives were further checked for anti-bacterial activities by paper disc diffusion method against Pseudomonas aeruginosa and Staphylococcus aureus bacterial strains.
TL;DR: The ligational behavior of an isatinic quinolyl hydrazone is checked to check the effect of anion for the same metal ion from either the geometry of the isolated complexes or the various modes of bonding.
Abstract: The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H2L). A phenolic quinolyl hydrazone (H2L) was allowed to react with various copper(II)- salts (Cl‾, Br‾, NO3‾, ClO4‾, AcO‾, SO42-). The reactions afforded dimeric complexes (ClO4‾, AcO‾ ), a binuclear complex (NO3‾ ) and mononuclear complexes (the others; Cl‾, Br‾, SO42-). The isolated copper(II)- complexes have octahedral, square pyramid and square planar geometries. Also, they reflect the strong coordinating ability of NO3‾, Cl‾, Br‾, AcO‾ and SO42- anions. Depending on the type of the anion, the ligand showed three different modes of bonding viz. (NN)0 for the mononuclear complexes (3, 4, 6), (NO)- with O- bridging for the dimeric complexes (1, 5) and a mixed mode [(NN)0 + (NO)- with O- bridging] for the binuclear nitrato- complex (2). The ligational behavior of the phenolic hydrazone (H2L) is highly affected by the type of the anion. The isolated copper(II)- complexes reflect the strong coordinating power of the SO42-, AcO‾, Br‾, Cl‾ and NO3‾ anions. Also, they reflect the structural diversity (octahedral, square pyramid and square planar) depending on the type of the counter anion.
TL;DR: The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described and compound 35 has been identified with efficacy in a xenograft model of HCT116 cells.
Abstract: The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described. In continuing our program aim to search for potent CDK4 inhibitors, the introduction of a thiazole group at the hydrazone part has led to marked enhancement of chemical stability. Furthermore, by focusing on the optimization at the C-4′ position of the thiazole ring and the C-6 position of the thieno[2,3-d]pyrimidine moiety, compound 35 has been identified with efficacy in a xenograft model of HCT116 cells. In this paper, the potency, selectivity profile, and structure–activity relationships of our synthetic compounds are discussed.
TL;DR: Investigation of the utility of Nallylhydrazides as versatile chemical intermediates that allow for high yielding fragment coupling by way of hydrazone formation followed by a carbon–carbon bond-forming molecular rearrangement finds a “traceless” bond construction between two fragments.
Abstract: Allylic hydrazines react with aldehydes and alcohols to afford functionalized ether adducts.
TL;DR: In this article, the crystal structure of Zn2(L2)2(CH3COO) was determined and the presence of phenoxo-bridged binuclear zinc(II) complexes was revealed.
TL;DR: In this article, the Fe-catalyzed decomposition of sulfonylhydrazones gives rise to sulfones, and the reaction is quite general and allows the preparation of sulfones from a variety of aryl, alkyl, and α,β-unsaturated aldehydes and ketones.
TL;DR: Not only a mild and efficient preparation and convenient quantification of a conjugate between the polycationic α-polylysine and enzymes could be shown, but also the complete preservation of the enzymatic activity was shown.
TL;DR: Comparison of the inhibitory effects of sterol hydrazones (9-12) and azasterols (AZA1-AZA3) on SMT with the molecular electrostatic potential, negative isopotential energy surfaces and local ionization potential calculated via DFT methods showed that changes in the electronic moiety introduced by the N and O atoms were not as important as the additional flexibility of the side chain introduced by an extra methylene group.
TL;DR: The discussion of the outcome data of the prepared complexes indicates that the ligand behave as a bidentate and/or tridentate ligand and the electronic spectra of the complexes suggest octahedral geometries for all isolated complexes.
TL;DR: The deprotonated ligand acts as a dibasic tridentate (ONS) via phenolate oxygen, azomethine (CN), and thiolate (C-S) groups and molecular parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data such as IR and TGA results.
TL;DR: In this paper, the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R 2 SnLY] 2 was reported.
TL;DR: The hydrazone side chain introduced by the conjugated heterodiene system at the 5-position of the heterocycle represents a valuable functionality for accessing novel 5-acyl derivatives difficult to obtain by other methods.
TL;DR: In this article, the synthesis of azine derivatives from benzophenone hydrazone and ketones/aldehydes by simple physical grinding has been studied, using a sulfated anatase-titania (TiO 2 -SO 4 2− ) catalyst.