Hydrazone

About: Hydrazone is a research topic. Over the lifetime, 4853 publications have been published within this topic receiving 65160 citations. The topic is also known as: hydrazone.

Designing of novel zinc(II) Schiff base complexes having acyl hydrazone linkage: study of phosphatase and anti-cancer activities

Abstract: Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and phenyl(pyridin-2-yl)methanone respectively. Three bio-relevant mononuclear zinc(II) complexes [Zn(L1)Cl2]·2H2O (1), [Zn(L2)Cl2] (2) and [Zn(L3)Cl2] (3) were synthesized by treatment of zinc(II) chloride with the corresponding Schiff base ligands and characterised by the usual physicochemical techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal X-ray analysis. All complexes were able to hydrolyse the P–O bond of the phosphate monoester in 90% (v/v) DMSO–water medium using 4-nitrophenylphosphate (4-NPP) as the model substrate and the trend in their activity is 1 ≈ 2 > 3. On considering the highly efficient hydrolysis properties, complexes 1–3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human non-small lung carcinoma) cells. Complex 2 showed the highest IC50 values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time.

Formation of silicon centered spirocyclic compounds: reaction of N-heterocyclic stable silylene with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine.

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...

Comparison of boron-assisted oxime and hydrazone formations leads to the discovery of a fluorogenic variant

Abstract: We use kinetic data, photophysical properties, and mechanistic analyses to compare recently developed high-rate constant oxime and hydrazone formations. We show that when Schiff base formation between aldehydes and arylhydrazines is carried out with an appropriately positioned boron atom, then aromatic B–N heterocycles form irreversibly. These consist of an extended aromatic structure amenable to the tailoring of specific properties such as reaction rate and fluorescence. The reactions work best in neutral aqueous buffer and can be designed to be fluorogenic – properties which are particularly interesting in bioconjugation.