Showing papers on "Hydrazone published in 2010"
TL;DR: Bacterial activity of acyl-hydrazone and its complexes were studied against gram-positive bacteria: Staphylococcus aureus, Bacillus subtilis and gram-negative bacteria: Pseudomonas aeruginosa, Escherichia coli by using minimum inhibitory concentrations (MICs) method.
205 citations
TL;DR: The reaction of cyanoacetyl hydrazine with 3-acetylpyridine gave the hydrazide-hydrazone derivative 3, which was synthesized against three cancer cell lines and showed high inhibitory effects.
Abstract: The reaction of cyanoacetyl hydrazine (1) with 3-acetylpyridine (2) gave the hydrazide-hydrazone derivative 3. The latter compound undergoes a series of heterocyclization reactions to give new heterocyclic compounds. The antitumor evaluation of the newly synthesized products against three cancer cell lines, namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) was performed. Most of the synthesized compounds showed high inhibitory effects.
119 citations
105 citations
TL;DR: These findings implicate that the hydrogen-bonding donor ability is a key requirement for the binding-induced conformational switching, which allows for direct naked-eye detection of volatile amines under ambient conditions.
Abstract: An efficient triple azo coupling reaction between anilines and phloroglucinol furnished a series of C3-symmetric molecules 7−9 supporting multiple conjugation pathways that converge at the molecular core. A combination of 1H/13C NMR spectroscopy, X-ray crystallography, and density functional theory computational studies provided a coherent picture of the [n,π]-conjugated molecular core, which is best described as the tris(hydrazone) [rather than tris(azo)] tautomer stabilized by resonance-assisted hydrogen bonding. For a homologous series of compounds, an increase in the torsional angles between the planar molecular core and the peripheral aryl groups results in a systematic blue shift in the low-energy electronic transitions (7, 523 nm; 8, 505 nm; 9, 445 nm in CHCl3) that qualitatively correlates with the shrinkage of effective conjugation through structural distortion. Similar spectral shifts could also be induced by amine substrates that interact with the intramolecular hydrogen-bonding network to trig...
101 citations
TL;DR: Some of the synthesized compounds reflected two-folds less activity against Escherichia coli relative to Cefixime, and most compounds showed stronger antimicrobial activity against Gram-positive bacteria than Cefaclor and CefIXime.
99 citations
TL;DR: In this paper, the authors investigated the structure of the pyrazolone derivative N-(1-phenyl-3-methyl-4-propyl-pyrazolones-5)-salicylidene hydrazone (H2L) and its copper(II) complex [Cu2L2CH3OH]·2 CH3OH have been both synthesized and characterized by elemental analyses, IR spectroscopy, X-ray crystallography, theoretical calculation and pharmacological testing.
98 citations
TL;DR: A series of potential anti-oxidant and anti-bacterial N'-arylmethylidene-2-(3,4-dimethyl-5,5-dioxidopyrazolo[4,3-c][1,2]benzothiazin-2(4H)-yl)acetohydrazides was synthesized in a facile way starting from commercially available saccharine.
92 citations
TL;DR: The isolated compounds were characterized by their physical properties, elemental analysis, IR-, MS (EI)- and NMR-spectroscopy and the cytotoxic effect of these complexes against the fast growing head and neck squamous carcinoma cells SQ20B and SCC-25 has been studied.
90 citations
TL;DR: The metal complexes of the novel Schiff-base ligand, hesperetin-2-hydroxy benzoyl hydrazone, and its copper, zinc and nickel complexes were found to possess potent antioxidant activity and be better than the free ligand alone and some standard antioxidants like vitamin C and mannitol.
Abstract: A novel Schiff-base ligand (H5L), hesperetin-2-hydroxy benzoyl hydrazone, and its copper (II), zinc (II) and nickel (II) complexes (M·H3L) [M(II) = Cu, Zn, Ni], have been synthesized and characterized The ligand and Zn (II) complex exhibit green and blue fluorescence under UV light and the fluorescent properties of the ligand and Zn (II) complex in solid state and different solutions were investigated In addition, DNA binding properties of the ligand and its metal complexes have been investigated by electronic absorption spectroscopy, fluorescence spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements Results suggest that all the compounds bind to DNA via an intercalation binding mode Furthermore, the antioxidant activity of the ligand and its metal complexes was determined by superoxide and hydroxyl radical scavenging methods in vitro The metal complexes were found to possess potent antioxidant activity and be better than the free ligand alone and some standard antioxidants like vitamin C and mannitol
84 citations
TL;DR: In this article, the corrosion inhibition properties of isoniazid derivatives, namely N-(morpholino methyl) isatin-3-isonicotinoyl hydrazone (MIIH), N-(piperazino methyl), isatin 3-isin-3 -isonic-inhibitor-drug (PIIH) for mild steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss techniques.
79 citations
TL;DR: In this article, 3-(2-Hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione (H2L, 1) was synthesized by azocoupling of diazonium salts of 2-hydroxy 4-nitroaniline with pentane 2,4dione and shown to exist in the hydrazone tautomeric form in the free state.
Abstract: 3-(2-Hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione (H2L, 1) was synthesized by azocoupling of diazonium salts of 2-hydroxy-4-nitroaniline with pentane-2,4-dione and shown to exist in the hydrazone tautomeric form in the free state and in its new dicopper(II) complex [Cu2(H2O)2(μ-L)2] (2) whose X-ray crystal structure was determined. Complex 2 acts as a catalyst, under mild conditions, for the peroxidative oxidation (with H2O2) of cyclohexane to cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide, in MeCN/H2O, and for the aerobic TEMPO-mediated selective oxidation of benzylic alcohols to the corresponding aldehydes, thus showing that azoderivatives of β-diketones can be the suitable ligands for such types of reactions.
TL;DR: Compounds (III) and (V) are obtained as mixtures of E- and Z-isomers with the internal E-isomer predominating except for (Vb).
Abstract: Compounds (III) and (V) are obtained as mixtures of E- and Z-isomers with the internal E-isomer predominating except for (Vb).
TL;DR: In this article, a series of octahedral and square-planar Ni(II) complexes have been synthesized from two different types of hydrazone ligands, and the isolated complexes were characterized by means of analytical and spectroscopic techniques.
TL;DR: 3-aminopyrazole derivative 3 was utilized as key intermediate for the synthesis of pyrazolo[3,4-d]pyrimidine 5, pentaaza-as-indacene 6, triaza-cyclopenta[c]phenanthrene 7, pyrazol[1,5-a]pyridine 8, 9 and (dimethyl-pyrrol-1-yl)pyrazole 10 derivatives.
TL;DR: Azo-hydrazone and cis-trans tautomerisms have been firstly observed between two disperse yellow dyes and three neutral dye-metal complexes.
Abstract: Azo-hydrazone and cis–trans tautomerisms have been firstly observed between two disperse yellow dyes (cis/trans-HL1 and cis-HL2) and three neutral dye-metal complexes (one mononuclear NiII complex 3 and two CuII coordination polymers 4 and 5 formulated as [Ni(trans-L1)2(CH3OH)2]·2H2O, [Cu(cis-L1)2]n and [Cu(L3)(H2O)]n).
TL;DR: In this article, the reaction of n-butyltin trichloride, [BunSnCl3], and phenyltin tri-triclou glycolide with 2-acetylpyridine benzoyl hydrazone (H2AcPh), H2AcpClPh, H2 AcpNO2Ph, and 2acetyl pyridine para-chloro-benzoyl hydride (H 2AcPClPh) gave the most active compounds against Staphylococcus aureus
Abstract: Reaction of n-butyltin trichloride, [BunSnCl3], and phenyltin trichloride, [PhSnCl3], with 2-acetylpyridine benzoyl hydrazone (H2AcPh), 2-acetylpyridine para-chloro-benzoyl hydrazone (H2AcpClPh) and 2-acetylpyridine para-nitro-benzoyl hydrazone (H2AcpNO2Ph) gave [BunSn(2AcPh)Cl2] (1), [BunSn(2AcpClPh)Cl2] (2), [BunSn(2AcpNO2Ph)Cl2] (3), [PhSn(2AcPh)Cl2] (4), [PhSn(2AcpClPh)Cl2] (5) and [PhSn(2AcpNO2Ph)Cl2] (6) as products. Among the hydrazones H2AcpClPh proved to be the most active against Staphylococcus aureus and Candida albicans. Upon coordination the antibacterial activity of both tin and the hydrazones significantly increases. Complexes 2 and 5 revealed to be the most active as antimicrobial agents.
TL;DR: In this article, the first hyperpolarizability, infrared intensi- ties and Raman activities of quinoline-2-carbaldehyde benzoyl hydrazone (HQbH2O) were calculated theoretically using the Gaussian03 package of programs.
TL;DR: The structural and tautomeric characteristics of 3-(4-fluorophenylhydrazone)pentane-2,4-dione were studied using IR, 1H and 13C NMR spectroscopy, X-ray diffraction analysis and quantum-chemical calculations.
TL;DR: In this paper, the properties of polymeric complexes with 5-sulphadiazineazo-3-phenyl-2-thioxo-4-thiazolidine and various anions were studied.
TL;DR: In this article, pyruvic acid hydrazone ligands with different alkyltin salts were used to construct six new organotin(IV) compounds, which have been characterized by single crystal X-ray diffraction, elemental analysis, IR, 1H and 119Sn NMR.
TL;DR: The organic functionalized, ternary CuSnS cluster was obtained by a two-step reaction, first derivatization of carbonyl functionalized double-decker-like cage and ensuing reaction of the resulting hydrazone functionalized thiostannate with Na(2)S.
TL;DR: A general two-step synthesis of substituted 3-aminoindazoles from 2-bromobenzonitriles involving a palladium-catalyzed arylation of benzophenone hydrazone followed by an acidic deprotection/cyclization sequence is described.
Abstract: A general two-step synthesis of substituted 3-aminoindazoles from 2-bromobenzonitriles involving a palladium-catalyzed arylation of benzophenone hydrazone followed by an acidic deprotection/cyclization sequence is described. This procedure offers a general and efficient alternative to the typical S(N)Ar reaction of hydrazine with o-fluorobenzonitriles.
TL;DR: 4-N,N-diethylaminosalicylaldehyde hydrazone Schiff base and its analogues were synthesized and characterized and exhibited ratiometric fluorescent response to Zn(2+) over other metal ions in aqueous ethanol solution with neutral buffer.
Abstract: 4-N,N-diethylaminosalicylaldehyde hydrazone Schiff base (1) and its analogues (2-6) were synthesized and characterized by NMR, MS and elemental analysis. Compound 1 exhibited ratiometric fluorescent response to Zn(2+) over other metal ions in aqueous ethanol solution with neutral buffer. The complexation ratio, site and constant and the effect of pH value and water fraction on its fluorescent response to Zn(2+) were investigated.
TL;DR: Experimental results suggest that all the compounds can bind to DNA via an intercalation binding mode and the rare earth complexes were found to possess potent antioxidant activities that are better than those of the ligand alone.
Abstract: A new ligand, 3-carbaldehyde chromone-(benzoyl) hydrazone (L), was prepared by condensation of 3-carbaldehyde chromone with benzoyl hydrazine. Its four rare earth complexes have been prepared and characterized on the basis of elemental analyses, molar conductivities, mass spectra, (1)H NMR spectra, UV-vis spectra, fluorescence studies and IR spectra. The Sm(III) complex exhibits red fluorescence under UV light and the fluorescent properties of Sm(III) complex in solid state and different solutions were investigated. In addition, the DNA binding properties of the ligand and its complexes have been investigated by electronic absorption spectroscopy, fluorescence spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements. Experimental results suggest that all the compounds can bind to DNA via an intercalation binding mode. Furthermore, the antioxidant activities of the ligand and its complexes were determined by superoxide and hydroxyl radical scavenging methods in vitro. The rare earth complexes were found to possess potent antioxidant activities that are better than those of the ligand alone.
TL;DR: In this paper, an asymmetric Mannich-type reaction of hydrazone 1a with difluoroenoxysilane 2 using chiral phosphine-oxazoline ligand has been reported, giving the adduct 3a in good yields and moderate enantioselectivities under mild conditions.
Abstract: With the catalysis of Zn(OTf)2, Mannich-type reactions of various aromatic hydrazones 1 with difluoroenoxysilane 2 proceeded smoothly to produce 2,2-difluoro-3-oxo-benzohydrazides in 27% –78% yields in THF or DCM under mild conditions. An unexpected monofluorination of hydrazone 1m with difluoroenoxysilane 2 was also disclosed in this paper. The first example of the asymmetric Mannich-type reaction of hydrazone 1a with difluoroenoxysilane 2 using chiral phosphine-oxazoline ligand has been reported, giving the adduct 3a in good yields and moderate enantioselectivities under mild conditions.
TL;DR: This work establishes the capability of the MOA for studying aldehydes and ketones, a critical class of oxidized organic molecules of interest in planetary and in terrestrial environmental and health studies.
Abstract: A microchip CE method is developed for the analysis of two oxidized forms of carbon, aldehydes and ketones, with the Mars Organic Analyzer (MOA). Fluorescent derivitization is achieved in ∼15 min by hydrazone formation with Cascade Blue hydrazide in 30 mM borate pH 5–6. The microchip CE separation and analysis method is optimized via separation in 30 mM borate buffer, pH 9.5, at 20°C. A carbonyl standard consisting of ten aldehydes and ketones found in extraterrestrial matter is successfully separated; the resulting LOD depends on the reactivity of the compound and range from 70 pM for formaldehyde to 2 μM for benzophenone. To explore the utility of this method for analyzing complex samples, analyses of several fermented beverages are conducted, identifying ten aldehydes and ketones ranging from 30 nM to 5 mM. A Martian regolith simulant sample, consisting of a basalt matrix spiked with soluble ions and acetone, is designed and analyzed, but acetone is found to have a limited detectable lifetime under simulant Martian conditions. This work establishes the capability of the MOA for studying aldehydes and ketones, a critical class of oxidized organic molecules of interest in planetary and in terrestrial environmental and health studies.
TL;DR: Two series of N’(E)-heteroaromatic-isonicotinohydrazide derivatives have been synthesized and evaluated for in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv and can be considered an important starting point for the rational design of new leads for anti-TB compounds.
Abstract: Two series of N’(E)-heteroaromatic-isonicotinohydrazide derivatives (3a-f and 4a-b) and 1-(7-chloroquinolin-4-yl)-2-[(heteroaromatic)methylene]hydrazone derivatives (5a-f and 6a-b) have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv. Several compounds were noncytotoxic and exhibited significant minimum inhibitory concentration (MIC) activity (3.12, 2.50, 1.25, or 0.60 μg/mL), which can be compared to that of the first-line drugs ethambutol (3.12 μg/mL) and rifampicin (2.0 μg/ml). These results can be considered an important starting point for the rational design of new leads for anti-TB compounds.
TL;DR: Simultaneous treatment with all mixed forms of the polymeric derivatives of doxorubicin significantly increased antitumor efficacy after application of monoconjugates, suggesting a synergizing effect that could be used in designing new doxorbicin-containing therapeutic systems.
Abstract: The cytostatic effects of polymeric conjugates based on N-(2-hydroxypropyl)methacrylamide copolymers (PHPMA) and containing doxorubicin bound through amide and hydrazone bonds (mixed conjugates) were compared with the cytostatic effects of monoconjugates containing drug bound through an amide or hydrazone bond. One group of mixed conjugates was formed from two comonomers containing doxorubicin bound to the methacryloyl group through a spacer and an amide (DOXAM) or hydrazone (DOXHYD) bond via copolymerization with HPMA. A second group of mixed conjugates was formed from two different interconnected HPMA copolymers, one containing DOXAM and the other DOXHYD, forming a high-molecular-weight branched structure. The third mixed polymeric system was a simple mixture of monoconjugates DOXAM−PHPMA and DOXHYD−PHPMA. Simultaneous treatment with all mixed forms of the polymeric derivatives of doxorubicin significantly increased antitumor efficacy after application of monoconjugates, suggesting a synergizing effect ...
TL;DR: In this paper, the authors reveal the origin of stereoselectivity in the deprotonation−alkylation of chiral N-amino cyclic carbamate (ACC) hydrazones.
Abstract: Density functional theory calculations and experiment reveal the origin of stereoselectivity in the deprotonation−alkylation of chiral N-amino cyclic carbamate (ACC) hydrazones. When the ACC is a rigid, camphor-derived carbamate, the two conformations of the azaenolate intermediate differ in energy due to conformational effects within the oxazolidinone ring and steric interactions between the ACC and the azaenolate. An electrophile adds selectively to the less-hindered π-face of the azaenolate. Although it was earlier reported that use of ACC auxiliaries led to α-alkylated ketones with er values of 82:18 to 98:2, B3LYP calculations predict higher stereoselectivity. Direct measurement of the dr of an alkylated hydrazone prior to removal of the auxiliary confirms this prediction; the removal of the auxiliary under the reported conditions can compromise the overall stereoselectivity of the process.
TL;DR: The packing arrangement molecules in crystals of AMBTH-H(2), the redox features of the AMB TH-hexamolybdate hybrid together with a good electronic communication between the organic pi system and the molybdenum centres make these compounds very promising blocks for the synthesis of conducting molecular materials.
Abstract: The electroactive benzothiazole hydrazone AMBTH-H(2), a new member of the 2,2'-azino-bis(N-alkylbenzothiazole) family, was synthesised in a five-step procedure and characterised by using X-ray diffraction along with two intermediates and the N-methylbenzothiazole hydrazone MBTH-H(2). Both AMBTH-H(2) and MBTH-H(2) were coupled to [Mo(6)O(19)](2-) in acetonitrile in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine to give two new diazoalkane-hexamolybdates, which were isolated as tetrabutylammonium salts and characterised by using IR, UV/Vis and NMR spectroscopies, cyclic voltammetry and, for one of them, X-ray diffraction. The packing arrangement molecules in crystals of AMBTH-H(2), the redox features of the AMBTH-hexamolybdate hybrid together with a good electronic communication between the organic pi system and the molybdenum centres make these compounds very promising blocks for the synthesis of conducting molecular materials.