Synthesis and characterization of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with acetylacetone bis-benzoylhydrazone and acetylacetone bis-isonicotinoylhydrazone

Zhou

2005

Transition Met Chem

Six complexes, M(HL) 2 AE nH 2 O (M=Co, Ni and Fe; n=4) with two ligands, 2-carboxy-benzaldehydebenzoylhydrazone (H 2 L 1 ) and 2-carboxybenzaldehyde-(4¢-methoxy)benzoylhydrazone (H 2 L 2 ), have been synthesized and characterized on the basis of elemental analyses, molar conductivities, i.r. spectra and thermal analyses. In addition, the suppression ratio for O ÀÁ 2 (a) and the suppression ratio for OH AE (b) were determined with a 72 spectrophotometer. The 50% inhibition [IC 50 (a) and IC 50 (b)] of the complexes were studied. This study demonstrated that the complexes have activity in the suppression of O ÀÁ 2 (a) and OH AE (b). In general, the antioxidative activities increased as the concentration of these complexes increased up to a selected extent. The complexes exhibit more effective antioxidants than the ligands and the series of the ligand (H 2 L 2 ) are better than the series of the ligand (H 2 L 1 ) do.

Section: Resultsmentioning

confidence: 96%

Synthesis, Characterization and Anti-oxidative Activity of Cobalt(II), Nickel(II) and Iron(II) Schiff Base Complexes

Zhou

2005

Transition Met Chem

“…The considerably high conductance values for some complexes may be ascribed to the partial solvolysis by dimethylsulfoxide [32,33].…”

Section: Molar Conductivitymentioning

confidence: 94%

Synthesis and characterization of transition metal complexes of N′-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methylene]thiophene-2-carbohydrazide

Fouda

Abd-Elzaher

Shakdofa

et al. 2007

Transition Met Chem

A hydrazone ligand (HL) containing the thiophene moiety has been prepared via condensation of thiophene-2-carbohydrazide with 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde. The complexes of copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), palladium(II), iron(III), ruthenium(III), uranyl(VI), and titanium(IV) with the ligand were prepared in good yield from the reaction of the ligand with the corresponding metal salts. The ligand and complexes were characterized using infrared, mass spectra, nuclear magnetic resonance, electronic absorption spectra, electron spin resonance, and magnetic moment measurements as well as elemental and thermal analyses. The results showed that the complexes are enolic by nature, whilst the ratio between the metal ion and the ligand depends on the acidity of the metallic ions and their oxidation numbers.

CHEMICAL & PHARMACEUTICAL BULLETIN

“…It shows that the nitrogen atom takes part in the coordination. 25) Weak bands at 490 cm Ϫ1 or so are assigned to n (M-N). It comfirms that the nitrogen atom of the imino-group bands to metal ion.…”

mentioning

confidence: 99%

Synthesis, Characterization, Antioxidative Activity and DNA Binding Properties of the Copper(II), Zinc(II), Nickel(II) Complexes with 1,2-Di(4′-iminonaringenin)ethane

Zhou

2008

DNA is an important cellular receptor, many chemicals exert their antitumor effects through binding to DNA thereby changing the replication of DNA and inhibiting the growth of tumor cells. 1,2) Then discussing the mechanism of compounds binding to DNA possesses significant meanings. As well-known to all of us, the interaction of small molecular ligands and its transition metal complexes with DNA has been the main subject of intense investigations for almost half of a century.3) Because of the unusual binding properties and general photoactivity, these complexes are suitable candidates as DNA secondary structure probes, antitumor drugs and photocleavers. The design of small complexes that can bind to DNA becomes more and more important. [4][5][6] It has been proposed that reactive oxygen species (ROS) are involved in the pathogeneses of various diseases, such as lifestyle-related diseases including hypertension 7) and photoaging due to exposure to ultraviolet radiation. 8) Free radicals are species that contain unpaired electrons. In the human body, superoxide and hydroxyl radicals are produced by the reduction of oxygen.9) Over production of free radicals is considered to be the main contributor to oxidative stress. The oxygen radicals may induce some oxidative damages to biomolecules such as carbohydrates, proteins, lipids, and DNA, thus accelerating aging, cancer, cardiovascular diseases, inflammation and so on. 10)Flavonoids are a large group of phenolic plant constituents. They are broadly distributed in vascular plants and responsible for most of the colors in nature.11) To date, more than 6000 flavonoids have already been identified, although only a smallar number is important from a dietary point of view.12) Recently, flavonoids receive considerable attention in the literature, mainly because of their biological and physiological importance. 13) They are potentially antioxidant, antibacterial, anticancer, anti-inflammatory and antiallergenic agents since they stimulate or inhibit a wide variety of enzyme systems as pharmacological agents.14-17) Naringenin (4Ј,5,7-trihydroxyflavanone) is one of the lesser-known flavonoids except for its use as antibacterial and anticancer agents.18) It is a flavanone compound that alters critical cellular processes such as cell multiplication, glucose uptake, and mitochondrial activity. 19) Many transition metals, such as copper, zinc and nickel, are important trace metals in human body. In order to gain more knowledge on naringenin, a new ligand, (1,2-di(4Ј-iminonaringenin)ethane, H 6 L) and its three transition metal complexes were synthesized. The interactions of the ligand and complexes with calf thymus DNA (CT DNA) using absorption spectroscopy, fluorescence spectroscopy, ethidium bromide(EB) displacement experiments, and viscosity measurement were studied for the first time. The antioxidative activity of the ligand and its transition metal complexes was also investigated. Information obtained from present work will be useful to understand the mechanism of interaction...