Use of cloud point extraction with derivatizing reagent for the extraction and determination of isoniazid

A simple and sensitive cloud point extraction high-performance liquid chromatography method is proposed for the determination of isoniazid in blood. The procedure is based on the product of the reaction of isoniazid with benzaldehyde. It can be validated that there is a linear relationship between the signal of isonicotinyl hydrazone and the concentration of isoniazid. A cloud point extraction system of nonionic surfactant Triton X-100 is applied for preconcentration of isonicotinyl hydrazone. Then the analytes in surfactant-rich phase are detected with HPLC-UV system. calibration graph was obtained in the range of 2.0 × 10(-3)-0.5 mg/L, the detection limit was 5.0 × 10(-4) mg/L. Method validation is performed on serum samples spiked at two levels, the recoveries ranging from 82.17-83.81%, with relative standard deviations from 2.45% to 3.89%.     

Metal complexes of isonicotinic acid hydrazide

Complexes of platinum(IV), ruthenium(III), rhodium(III), iridium(III), gold(III), dioxouranium(II), zinc(II), cadmium(II), mercury(II) and manganese(II) with isonicotinic acid hydrazide were prepared and characterized on the basis of analytical, conductometric, magnetic susceptibility and spectral data. Platinum(IV) ruthenium(III), rhodium(III), iridium(III), dioxouranium(II) and manganese(II) form six-coordinate complexes while gold(III), zinc(II), cadmium(II) and mercury(II) form four coordinate complexes.     

One-Pot Ozonolytic Synthesis of Isoniazid Derivatives from (–)-α-Pinene and Δ<Superscript>3</Superscript>-Carene

Optically active isoniazid derivatives containing a cyclopropane or cyclobutane fragment have been synthesized by ozonolysis of (+)-Δ³-carene and (–)-α-pinene, followed by treatment of the ozonolysis products with isonicotinic acid hydrazide.     

Hydrazone as complexing agent: Synthesis,structural characterization and biological studies of some complexes

This paper deals with the synthesis, magnetic, spectral, thermal, and biological studies of Ti(III), VO(IV), Cr(III), Mn(III), Fe(III), and Zr(IV) complexes with chelating hydrazone derived from 2-hydroxy-5-methylacetophenone and furoic acid hydrazide. The acid hydrazone synthesized is 2-hydroxy-5-methylace-tophenone-furoylhydrazone. The ligand has been characterized on the basis of IR and ¹H NMR spectra. The presence of water molecules and thermal stabilities of the complexes are also reported. Solid-state electrical conductivity was measured over a 313–410-K temperature range, and the compounds show semiconducting behavior. The new complexes have been screened for their antibacterial and antifungal activity, and they show higher activity than free ligands.     

A kinetic and mechanistic study on oxidation of Isoniazid drug by alkaline diperiodatocuprate(III) – A free radical intervention

The kinetics of oxidation of isoniazid (INH) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.05 mol dm⁻³ has been studied spectrophotometrically. The reaction showed first order kinetics both in [DPC] and [INH] and negative less than unit order, both in alkali and periodate concentrations under the experimental conditions. Intervention of free radicals was observed in the reaction. Products of the reaction, isonicotinic acid and copper(II) have no effect on the rate of reaction. Ionic strength and dielectric constant did not affect the rate of reaction. Based on the observed orders and experimental evidences, a mechanism involving the monoperiodatocuprate(III) (MPC) as the reactive oxidant species has been proposed. The main products were identified by I.R, N.M.R. and GC-MS spectral studies. The reaction constants involved in the mechanism were evaluated. Investigations at different temperatures allowed the determination of the activation parameters with respect to the slow step of proposed mechanism. The mechanism proposed and the derived rate laws are consistent with the observed kinetics.     

The thermometric determination of isonicotinic acid hydrazide in isoniazid tablets

The determination of isonicotinic acid hydrazide in the dosage form of isoniazid tablets is done using thermometric titrimetry. The hydrazide is oxidized by hexacyanoferrate(III) ions. It is not necessary to separate the active ingredients from the powdered sample. The results from the proposed method are compared with those obtained using the standard B.P. method.     

Spectroscopic and theoretical study of the o-vanillin hydrazone of the mycobactericidal drug isoniazid

A complete and detailed study of the hydrazone obtained from condensation of antituberculous isoniazid (hydrazide of the isonicotinic acid, INH) and o-vanillin (2-hydroxy-3-methoxybenzaldehyde, o-HVa) is performed. It includes structural and spectroscopic analyses, comparing experimental and theoretical results. The compound was obtained as a chloride of the pyridinic salt (INHOVA⁺Cl^?) but it will be referred as INHOVA for the sake of simplicity. The conformational space was searched and optimized geometries were determined both in gas phase and including solvent effects. Vibrational (IR and Raman), electronic and NMR spectra were registered and assigned with the help of computational methods based on the Density Functional Theory. Isoniazid hydrazones are good candidates for therapeutic agents against tuberculosis with conserved efficiency and lower toxicity and resistance than parent INH.     

Coulometric titration of benzoic and isonicotinic acid derivatives of hydrazides and acylhydrazones

It was found that benzoic acid hydrazides rapidly and quantitatively react with electrogenerated chlorine and bromine under the conditions of galvanostatic coulometry. Benzoic acid hydrazides were determined in model solutions. A good precision (RSD varied from 1 to 6%) allowed coulometry to be applied to the determination of isonicotinic acid hydrazide in isoniazid tablets and isonicotinic acid 3-methoxy-4-hydroxybenzylidenehydrazide in phthivazid tablets.     

Coulometric redox titrations of hydrazine,phenylhydrazine and isoniazid with electrogenerated lead(IV) acetate and manganese(III) acetate in acetic acid

Summary The conditions fox coulometric determination of small quantities of hydrazine, phenylhydrazine and isoniazid in glacial acetic acid with electrogenerated manganese(III) acetate and lead(IV) acetate were investigated. With the direct coulometric method at room temperature, good results were obtained in the determination of hydrazine and isoniazid with lead(IV) acetate and in the determination of phenylhydrazine with manganese(III) acetate. Hydrazine and isoniazid can also be determined by the coulometric back-titration method if the oxidation with manganese(III) acetate is performed at elevated temperature.

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Zusammenfassung Die Bedingungen für die coulometrische Bestimmung kleiner Mengen Hydrazin, Phenylhydrazin und Isoniazid mit elektrolytisch erzeugtem Mangan(III)-Acetat und Blei(IV)-Acetat in Eisessig wurden untersucht. Bei Zimmertemperatur wurden gute Resultate durch direkte coulometrische Titration des Hydrazins und Isoniazids mit Blei(IV)-Acetat und bei Titration des Phenylhydrazins mit Mangan(III)-Acetat erhalten. Durch coulometrische Rücktitration können bei höheren Temperaturen Hydrazin und Isoniazid mit Mangan(III)-Acetat erfolgreich bestimmt werden.

     

A simple and rapid fluorimetric method for the microdetermination of isonicotinic acid hydrazide

A simple, rapid and sensitive fluorimetric method has been developed for the microdetermination of isonicotinic acid hydrazide, based on its formation of a hydrazone with 2-hydroxy-1-naphthaldehyde in acidic medium, in the presence of excess of scandium ions, and the consequent formation of a strongly fluorescent complex (lambda(ex) 430 nm, lambda(em) 510 nm) between the hydrazone and scandium in weakly acidic medium. Kinetic and equilibrium procedures for isonicotinic acid hydrazide determination are proposed. A calibration graph linear up to 5.00 mug/ml is obtained by both procedures, with a mean relative error of about 2.0%. The detection limit for the kinetic procedure is 0.4 ng/ml and for the equilibrium procedure about 0.2 ng/ml.     

以Schiff base为配体的Cu(Ⅱ)-金属凝胶的制备和表征

以间苯二甲醛分别与异烟肼、烟酸酰肼和2-吡啶甲酰肼反应,合成了3种含吡啶环的Schiff base配体间苯二甲醛双缩4-吡啶甲酰腙(S1)、间苯二甲醛双缩3-吡啶甲酰腙(S2)和间苯二甲醛双缩2-吡啶甲酰腙(S3);测试了这3个化合物与醋酸铜通过配位作用在不同溶剂中形成金属凝胶的能力,结果发现,配体S1与醋酸铜在DMF/H_2O和DMSO/H_2O的混合溶剂中、配体S3与醋酸铜在DMF/H_2O的混合溶剂中均可以形成金属凝胶。胶凝测试结果表明,吡啶环上N原子位置的不同,对化合物形成金属凝胶的能力有极大影响。利用扫描电子显微镜(SEM)观察了金属凝胶的微观形貌,结果表明,配体分子的结构对金属凝胶的微观形貌也有较大影响;红外光谱和紫外可见光谱的研究证明了配位作用在金属凝胶形成过程中的推动作用;X射线衍射分析(XRD)研究表明,配体S1与醋酸铜在两种混合溶剂中形成的金属凝胶均表现出了四方堆积结构。     

Structural similarities among eight benzoylhydrazones

The crystal structures of eight benzoylhydrazones with different substituents have been investigated, namely 1‐benzoyl‐2‐(propan‐2‐ylidene)hydrazone, C₁₀H₁₂N₂O, (I), 1‐benzoyl‐2‐(1‐cyclohexylethylidene)hydrazone, C₁₅H₂₀N₂O, (II), 1‐benzoyl‐2‐[1‐(naphthalen‐2‐yl)ethylidene]hydrazone, C₁₉H₁₆N₂O, (III), 1‐benzoyl‐2‐(1‐cyclohexylbenzylidene)hydrazone, C₂₀H₂₂N₂O, (IV), 1‐benzoyl‐2‐(1‐phenylbenzylidene)hydrazone, C₂₀H₁₆N₂O, (V), 1‐benzoyl‐2‐[1‐(4‐chlorophenyl)benzylidene]hydrazone, C₂₀H₁₅ClN₂O, (VI), 1‐benzoyl‐2‐(4‐hydroxybenzylidene)hydrazone methanol monosolvate, C₁₄H₁₂N₂O₂·CH₃OH, (VII), and 1‐benzoyl‐2‐(1,1‐diphenylpropan‐2‐ylidene)hydrazone, C₂₂H₂₀N₂O, (VIII). The ten molecules in the eight crystal structures [there are two independent molecules in the structures of (V) and (VI)] show similar conformations and hydrogen‐bonding patterns. The C=N—NH—C=O group is planar, but the plane of the phenyl ring of the benzoyl group is rotated by about 30° with respect to that of the keto group [except for (IV), where the groups are coplanar]. Only in the amide group of (VIII) is the N—H group syn to the C=O bond, whereas the seven other compounds exhibit the anti conformation. Unless prevented by steric hindrance, N—H...O hydrogen bonds help to stabilize the crystal structure, which leads to infinite chains or dimers depending upon the molecular conformation. The molecular packing is supported by intermolecular C—H...O interactions. In the crystal structure of (VII), the methanol solvent molecule participates in two strong hydrogen bonds and two weak C—H...O interactions, thus acting as a link between the molecular chains.     

Structural comparisons between methylated and unmethylated nitrophenyl lophines

The lophine derivative 2‐(2‐nitrophenyl)‐4,5‐diphenyl‐1H‐imidazole, C₂₁H₁₅N₃O₂, (I), crystallized from ethanol as a solvent‐free crystal and from acetonitrile as the monosolvate, C₂₁H₁₅N₃O₂·C₂H₃N, (II). Crystallization of 2‐(4‐nitrophenyl)‐4,5‐diphenyl‐1H‐imidazole from methanol yielded the methanol monosolvate, C₂₁H₁₅N₃O₂·CH₄O, (III). Three lophine derivatives of methylated imidazole, namely, 1‐methyl‐2‐(2‐nitrophenyl)‐4,5‐diphenyl‐1H‐imidazole methanol solvate, C₂₂H₁₇N₃O₂·CH₄O, (IV), 1‐methyl‐2‐(3‐nitrophenyl)‐4,5‐diphenyl‐1H‐imidazole, C₂₂H₁₇N₃O₂, (V), and 1‐methyl‐2‐(4‐nitrophenyl)‐4,5‐diphenyl‐1H‐imidazole, C₂₂H₁₇N₃O₂, (VI), were recrystallized from methanol, acetonitrile and ethanol, respectively, but only (IV) produced a solvate. Compounds (III) and (IV) each crystallize with two independent molecules in the asymmetric unit. Five imidazole molecules in the six crystals differ in their molecular conformations by rotation of the aromatic rings with respect to the central imidazole ring. In the absence of a methyl group on the imidazole [compounds (I)–(III)], the rotation angles are not strongly affected by the position of the nitro group [44.8 (2) and 45.5 (1)° in (I) and (II), respectively, and 15.7 (2) and 31.5 (1)° in the two molecules of (III)]. However, the rotation angle is strongly affected by the presence of a methyl group on the imidazole [compounds (IV)–(VI)], and the position of the nitro group (ortho, meta or para) on a neighbouring benzene ring; values of the rotation angle range from 26.0 (1) [in (VI)] to 85.2 (1)° [in (IV)]. This group repulsion also affects the outer N—C—N bond angle. The packing of the molecules in (I), (II) and (III) is determined by hydrogen bonding. In (I) and (II), molecules form extended chains through N—H...N hydrogen bonds [with an N...N distance of 2.944 (5) Å in (I) and 2.920 (3) Å in (II)], while in (III) the chain is formed with a methanol solvent molecule as the mediator between two imidazole rings, with O...N distances of 2.788 (4)–2.819 (4) Å. In the absence of the imidazole N—H H‐atom donor, the packing of molecules (IV)–(VI) is determined by weaker intermolecular interactions. The methanol solvent molecule in (IV) is hydrogen bonded to imidazole [O...N = 2.823 (4) Å] but has no effect on the packing of molecules in the unit cell.     

Co(II)与烟酸类分子形成的配位聚合物的晶体结构与孔道稳定性

利用烟酸与异烟酸两种配体分别与硝酸钴在N,N'-二甲基甲酰胺(DMF)中采用溶剂热法合成了三种新的配位聚合物[CO₂(μ₂-H₂O)(nicotinic acid)₄·(DMF)] (1), [CO₂(isonicotinic acid)₄·(DMF)] (2), [Co(isonicotinicacid)₂·(DMF)] (3), 并利用单晶X射线衍射(XRD)和元素分析获得其结构信息. 通过傅里叶变换红外(FTIR)光谱、粉末X射线衍射(XRD)、热重分析(TGA)和比表面积分析等手段对结构中孔道的热稳定性进行了表征. 结果表明化合物1 具有类金刚石的拓扑结构, 结构中含有稳定的一维(1D)孔道空间. 化合物2 和3 是以异烟酸为配体, 分别在100 和160 °C下合成, 二者结构中配体以完全不同的方式与Co(II)配位, 从而使其具有不同的结构.化合物2和3的一维孔道在热处理脱附DMF分子的过程中不能稳定存在.     

Kinetics and mechanism of the reaction between aquacobalamin and isoniazid

Kinetics of the reaction of aquacobalamin (H₂OCbl) with isoniazid (isonicotinic acid hydrazide, INH) in weakly alkaline, neutral, and weakly acidic media was studied using UV–Vis spectroscopy. It is shown that the reversible formation of a complex more stable than those of cobalamin(III) with pyridine and hydrazine occurs during the reaction. A mechanism of the reaction includes reversible stages of binding a neutral INH molecule by cobalamin(III) through an oxygen atom with its subsequent deprotonation, along with the reversible interaction of H₂OCbl and the negatively charged form of INH.     

Synthesis and Crystal Structure of Isonicotinic Acid [1-（3,5-Dibromo-2- hydroxyphenyl）methylidene]hydrazide Methanol

A new Schiff base compound, C13H9Br2N3O2·CH3OH, isonicotinic acid [1-(3,5- dibromo-2-hydroxyphenyl)methylidene]hydrazide methanol, has been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The compound comprises a Schiff base moiety isonicotinic acid [1-(3,5-dibromo-2-hydroxyphenyl) methylidene]hydrazide and a methanol molecule. The crystal belongs to the triclinic system, space group P1 with a = 8.464(1), b = 9.511(2), c = 10.901(2) , α = 92.940(2), β = 110.456(2), γ = 96.040(2)o, Z = 2, V = 814.0(2) 3, Dc = 1.759 g/cm3, Mr = 431.09, λ(MoKα) = 0.71073 , μ = 4.994 mm-1, F(000) = 424, R = 0.0440 and wR = 0.1061. A total of 3284 unique reflections were collected, of which 2197 with I > 2σ(I) were observed. The molecule adopts a trans configuration about the C=N double bond. The dihedral angle between the benzene and pyridine rings is 22.0(4)o. The crystal structure is stabilized by intermolecular O-H···N and C-H···O hydrogen bonds, forming layers parallel to the ac plane. The preliminary biological tests show that the compound has potential antibacterial activities.     

Determination of isonicotinic acid hydrazide (isoniazid) by the weisz ring-oven technique

A simple precise method is described for the determination of isonicotinic acid hydrazide (isoniazid) alone, and in mixtures with aspirin, paracetamol and streptomycin, by reaction with vanillin in the Weisz ring-oven technique; 0.1–15 μg of isoniazid can be determined with errors of 2–2.7%.     

Complexation and back extraction of various metals by water-soluble diglycolamide.

Water-soluble ligands, N,N,N',N'-tetramethyldiglycolamide (TMDGA), N,N,N',N'-tetraethyldiglycolamide (TEDGA), N,N,N',N'-tetrapropyldiglycolamide (TPDGA) and N,N-dipropyldiglycolamic acid (DPDGAc) were prepared and their abilities to complex with and to back-extract the metal cations were investigated. These results indicate that the DGA series and DPDGAc have a stronger complexing ability with Am(III) and Pu(IV) than comparable carboxylic and aminopolycarboxylic acids. Among these ligands, the trend of the strength of their complexing ability is TPDGA approximately TEDGA > TMDGA approximately DPDGAc. TPDGA has significant loss to the extraction solvent due to its high hydrophobicity. It is evident from the present work that TEDGA is the best reagent for the reverse-extraction of not only An(III), (IV) but also Ca(II), Sc(III), Y(III), Zr(IV), La(III), Hf(IV), and Bi(III).     

Synthesis of N,N’-dimethyl-3-oxa-glutamic acid and application in the simplification of TRPO process

To simplify TRPO process, a novel ligand, N,N’-dimethyl-3-oxa-glutaramic acid (DMOGA), was synthesized and used for stripping of An(III, IV) from 30% TRPO-kerosene. The distribution ratios for transuranium elements, including Np(IV), Pu(IV), Am(III), and some fission products, including Eu(III), Fe and Zr between 30% TRPO-kerosene and various HNO₃-DMOGA solutions were measured. An(III, IV) and Ln(III) extracted to TRPO from simulated high level liquid waste could be recovered with an efficiency of 99.9% above in one stream with a 3-stage crosscurrent strip experiment with 0.2M DMOGA in HNO₃ solution. Using this new agent, the back extraction of TRU elements from loaded TRPO phase becomes more simple and practical. Therefore, the original TRPO process could be simplified.     

Resacetophenone isonicotinic acid hydrazone as a reagent for the catalytic polarographic determination of nanogram quantities of vanadium(V)

The polarographic method proposed for 1–12 ng of vanadium(V) is based on the reduction of bromate, catalysed by the metal ion, with resacetophenone isonicotinic acid hydrazone at pH 5.0. Only iron interferes seriously.