4-Hydroxy-2-methyl-N-(2-thiazole)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (EX15) and its Cu(II) Complex as New Oxicam Selective Cyclooxygenase-2 Inhibitors

4-Hydroxy-2-methyl-N-(2-thiazole)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (EX15) as nonsteroidal antiinflammatory drug (NSAIDs) of oxicam family has been synthesized bearing high se-lectivity for cyclooxygenase-2 (COX-2) inhibition and high ability to chelate with Cu(II) ions. The EX15-Cu(II) complex, and [Cu(EX15)(OAc)(H2O)2], were synthesized and characterized by using elemental analysis, spectral (UV-Vis, IR), conductance, thermal and magnetic studies. Two equations were predicted using quantitative structure activity relationship (QSAR) and regression analysis for the COX-2 and COX-1 selectivity (microsomal assay) with a regression correlation (R) close to unity. Two techniques were used to investigate the validity of these equations; macrophage cell line (in vitro) selectivity and collagen-adjuvant arthritis model in rats (in vivo) which showed a significant antioxidant, analgesic and antirheumatic effect for 4-hydroxy-2-methyl-N-(2-thiazole)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide and its Cu(II) complex, [Cu(EX15)(OAc)(H2O)2]. (doi: 10.5562/cca1802

Chelation activity of N'1,N'6-bis((E)-3,4-dihydroxybenzylidene)adipohydrazide towards some transition metal ions

New chelating agent, N'1,N'6-bis((E)-3,4-dihydroxybenzylidene)adipohydrazide (DBAH) was synthesized and its crystal structure was analyzed by X-ray single crystal diffractometer. Homometallic complexes of Zr(IV), Co(II), Ni(II), Cu(II), Cd(II) and heterometallic complex of Co(II)/Zn(II) or Co(II)/Zn(II)/Cd(II) have been synthesized and characterized by spectroscopic and physicochemical methods. The data confirms the formation of bi- and tetra-metallic complexes. The ligand behaves as a neutral tetradentate in the Co(II) and Ni(II) complexes; tetranegative tetradentate in Zr(IV) and Cd(II) complexes and binegative octadentate in [Co2Zn2(DBAH)Cl6] and [Co2ZnCd(DBAH-4H)(H2O)4Cl4].H2O. A tetrahedral structure was proposed for the Ni(II), Zr(IV) and Co(II)/Zn(II) complexes; square-planar for the Cu(II) complex and octahedral geometry for the Co(II) complex. The ESR spectrum confirms the proposed structure of the Cu(II) complex. The thermal analyses confirm the stability of these complexes in the range 275-418 °C. The molecular modeling of [Co2Zn2(DBAH)Cl8] was drawn and its parameters were calculated

Flotation, speciation and determination of iron(III) using aluminon in water, real samples and wastes of power stations

Aluminon has been investigated for the separation of iron(III) by flotation technique. This reagent formed a 1:1 stable complex in aqueous solution. An intense violet layer is formed after flotation using oleic acid (HOL). A highly selective and sensitive spectrophotometric procedure is proposed for the determination of Fe(III) after overcoming all interferences. Preliminary studies show the possibility of forming a complex with Fe(II) to an extremely low extent. Trials have been carried out to separate Fe(II) and Fe(III) using NH4SCN or NaF. To prevent the oxidation of Fe(II), NaBH4 is used.  The separation of Fe(III) and Fe(II) can be achieved using 0.6 mg L-1 NaBH4.  The flotation- determination method was carried out at pH 2-3. The formation constant is 1.3×107 L mol-1 with molar absorptivity of 0.2×105 L mol-1 cm-1 and detection limit of 5×10-6 mol L-1. The effect of foreign ions is avoided using excess aluminon and 0.5 mg L-1 NaBH4. The proposed procedure was applied to synthetic mixtures [Fe(III) + Fe(II)], Fe(III) and some cations, wastes of power stations, simulated samples and real ores

The ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions

<p>Abstract</p> <p>Background</p> <p>The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H₂L).</p> <p>Results</p> <p>A phenolic quinolyl hydrazone (H₂L) was allowed to react with various copper(II)- salts (Cl‾, Br‾, NO₃‾, ClO₄‾, AcO‾, SO₄^2-). The reactions afforded dimeric complexes (ClO₄‾, AcO‾ ), a binuclear complex (NO₃‾ ) and mononuclear complexes (the others; Cl‾, Br‾, SO₄^2-). The isolated copper(II)- complexes have octahedral, square pyramid and square planar geometries. Also, they reflect the strong coordinating ability of NO₃‾, Cl‾, Br‾, AcO‾ and SO₄^2-anions. Depending on the type of the anion, the ligand showed three different modes of bonding <it>viz</it>. (NN)⁰for the mononuclear complexes (<b>3, 4, 6</b>), (NO)^-with O- bridging for the dimeric complexes (<b>1, 5</b>) and a mixed mode [(NN)⁰+ (NO)^-with O- bridging] for the binuclear nitrato- complex (<b>2</b>).</p> <p>Conclusion</p> <p>The ligational behavior of the phenolic hydrazone (H₂L) is highly affected by the type of the anion. The isolated copper(II)- complexes reflect the strong coordinating power of the SO₄^2-, AcO‾, Br‾, Cl‾ and NO₃‾ anions. Also, they reflect the structural diversity (octahedral, square pyramid and square planar) depending on the type of the counter anion.</p

The ligational behavior of an isatinic quinolyl hydrazone towards copper(II)- ions

<p>Abstract</p> <p>Background</p> <p>The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone.</p> <p>Results</p> <p>New homo- and heteroleptic copper(II)- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL) with several copper(II)- salts <it>viz. </it>Clˉ, Brˉ, NO₃ˉ, ClO₄^-, SO₄^2-and AcO^-. The obtained complexes have O_h, T_dand D_4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO₃ˉ and SO₄^2-anions. Depending on the type of the anion, the ligand coordinates the copper(II)- ions either through its lactam (NO₃ˉ and ClO₄^-) or lactim (the others) forms.</p> <p>Conclusion</p> <p>The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (O_h, T_dand D_4h) or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO₃ˉ and SO₄^2-anions in consistency with the donor ability of the anions. In case of copper(II)- acetate, a unique homoleptic complex (<b>5</b>) was obtained in which the AcO^-anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.</p

Spectral, thermal, optical and biological studies on (E)-4-[(2-hydroxyphenyl)imino]pentan-2-one and its complexes

Metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates and (E)-4-(2-hydroxyphenylimino)pentan-2-one (H2L) have been synthesized and characterized by elemental analyses, MS, IR, UV-Vis., 1H NMR, thermal analyses (TGA and DTG) and magnetic measurements. In all complexes except for Zn(II) complex, the Schiff base ligand acts as a mono-negative tridentate (NOO) donor, through the azomethine nitrogen, the hydroxyl oxygen and the enolic carbonyl oxygen. The structure of the Cu(II) complex is square-planar, the Co(II) is octahedral while, the Ni(II) and Zn(II) are tetrahedral. The optical band gap measurements indicated a semi-conducting nature of these complexes. The biological activities have been screened against two bacteria and two fungi. Some of the studied complexes showed activity against bacteria and fungi