Search results for "hydrazone"

Reactive oxygen species derived from the mitochondrial respiratory chain are not responsible for the basal levels of oxidative base modifications obs…

2004

The mitochondrial electron transport chain (ETC) is the most important source of reactive oxygen species (ROS) in mammalian cells. To assess its relevance to the endogenous generation of oxidative DNA damage in the nucleus, we have compared the background (steady-state) levels of oxidative DNA base modifications sensitive to the repair glycosylase Fpg (mostly 7,8-dihydro-8-oxoguanine) in wild-type HeLa cells and HeLa rho0 cells. The latter are depleted of mitochondrial DNA and therefore are unable to produce ROS in the ETC. Although the levels of ROS measured by flow cytometry and redox-sensitive probes in rho0 cells were only 10-15% those of wild-type cells, steady-state levels of oxidativ…

Self-ordering of metallogrid complexes via directed hydrogen-bonding.

2012

Reaction of imidazole aldehydes with dihydrazino derivatives of 2-phenylpyrimidine provides a family of bis(acylhydrazone) ligands which form [2 × 2] metallogrid complexes with transition metal ions including Fe(II), Co(II), Cu(II) and Zn(II). The free ligands show H-bonding interactions, both donor and acceptor, largely involving the imidazole units, while binding of the metal ions occupies all the acceptor sites and leaves only the pyrrolic-NH site as an H-bond donor, although its deprotonation by a strong base can regenerate an acceptor. These H-bonding interactions have been studied by (1)H NMR spectroscopy in solution and in the solid state by means of several crystal structure determi…

Azine-bridged octanuclear copper(II) complexes assembled with a one-stranded ditopic thiocarbohydrazone ligand.

2005

Footprint of carbonyl compounds in hand scent by in-tube solid-phase microextraction coupled to nano-liquid chromatography/diode array detection

2019

Abstract In the present work, the footprint of carbonyl compounds in hand scent was achieved by a miniaturized method consisting of sampling with cotton gauze, extraction and derivatization using 2,4-dinitrophenylhydrazine (DNPH) and preconcentration, separation and detection by in-tube solid-phase microextraction (IT-SPME) coupled to nano-liquid chromatography/Uv–vis diode array detection. The coupling IT-SPME-nanoLC-DAD was solved by using a two-valve system: the first valve for loading the sample and the second one to perform IT-SPME. To this aim, a nanoparticle-based capillary column was employed. Firstly, the transfer time from the load loop to the NP-based capillary column in the IT-S…

Room temperature ionic liquids structure and its effect on the mononuclear rearrangement of heterocycles: an approach using thermodynamic parameters.

2006

The kinetics of the rearrangement of the Z-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1) into the relevant 4-benzoylamino-2,5-diphenyl-1,2,3-triazole (2) induced by amines have been studied in five room-temperature ionic liquids (RTILs) at different temperatures. The kinetic data collected show that both cationic and anionic parts of RTILs significantly influence the reactivity of the title reaction. The calculated activation parameters allow us to advance hypotheses about the weak interactions operating in RTIL solutions.

On the Rearrangement in Dioxane/Water of (Z)-Arylhydrazones of 5-Amino-3-benzoyl-1,2,4-oxadiazole into (2-Aryl-5-phenyl-2H-1,2,3-triazol-4-yl)ureas: …

2006

We have recently evidenced an interesting differential behavior in the reactivity in dioxane/water between the (Z)-2,4-dinitrophenylhydrazone (1a) and the (Z)-phenylhydrazone (1b) of 5-amino-3-benzoyl-1,2,4- oxadiazole. The former rearranges into the relevant triazole 2a only at pS+ > 4.5 while undergoing hydrolysis at high proton concentration (pS+ < 3.5); on the contrary, the latter rearranges into 2b in the whole pS+ range examined (0.1 e pS+ e 14.9). Thus, for a deeper understanding of these differences we have now collected kinetic data on the rearrangement in dioxane/water of a series of 3- or 4-substituted (Z)-phenylhydrazones (1c-l) of 5-amino-3-benzoyl-1,2,4-oxadiazole in a wide ra…

Synthesis, X-ray structure, Hirshfeld analysis, and DFT studies of a new Pd(II) complex with an anionic s-triazine NNO donor ligand

2020

A new Pd(II) complex, [Pd(Triaz)Cl], with the hydrazono-s-triazine ligand, 2,4-di-tert-butyl-6-((2-(4-morpholino-6-(phenylamino)-1,3,5-triazin-2-yl)hydrazono)methyl)phenol, was synthesized by the reaction of PdCl2 with the organic ligand (1:1) in acetone under isothermal conditions. The molecular structure of the [Pd(Triaz)Cl] complex was determined using FTIR and 1H NMR spectroscopic techniques, and single-crystal X-ray diffraction. Moreover, using Hirshfeld surface analysis, the percentages of the intermolecular interactions were determined. The obtained values were 60.6%, 11.6%, 8.1%, 3.6%, and 5.0% for the H⋯H, C⋯H, O⋯H, N⋯H, and Cl⋯H interactions, respectively. Among them, the O⋯H, C⋯H…

Development of stimulus-sensitive electrospun membranes based on novel biodegradable segmented polyurethane as triggered delivery system for doxorubi…

2022

In this work, redox-sensitive polyurethane urea (PUU) based electrospun membranes have been exploited to chemically tether a pH-sensitive doxorubicin derivative achieved by linking a lipoyl hydrazide to the drug via a hydrazone linkage. First, the lipoyl-hydrazone-doxorubicin derivative labelled as LA-Hy-Doxo has been syn- thesized and characterized. Then, the molecule has been tethered, via a thiol-disulfide exchange reaction, to the redox-sensitive PUU (PolyCEGS) electrospun membrane. The redox-sensitive PolyCEGS PUU has been produced by using PCL-PEG-PCL polyol and glutathione-tetramethyl ester (GSSG-OMe)4 as a chain extender. The LA-Hy- Doxo tethered electrospun membrane has showed a du…

CCDC 120949: Experimental Crystal Structure Determination

2000

Related Article: F.Hueso-Urena, M.N.Moreno-Carretero, A.L.Penas-Chamorro, J.M.Amigo, V.Esteve, T.Debaerdemaeker|1999|Polyhedron|18|3629|doi:10.1016/S0277-5387(99)00292-2

CCDC 119847: Experimental Crystal Structure Determination

2000

Related Article: F.Hueso-Urena, M.N.Moreno-Carretero, A.L.Penas-Chamorro, J.M.Amigo, V.Esteve, T.Debaerdemaeker|1999|Polyhedron|18|3629|doi:10.1016/S0277-5387(99)00292-2