DNA Binding Properties of Two Ruthenium(III) Complexes Containing Schiff Bases Derived from Salicylaldehyde: Spectroscopic and Electrochemical Evidence of CT DNA Intercalation

The interaction of CT DNA by two anionic Ru(III) complexes with N-substituted salicylidenimine ligands was investigated by spectroscopic titration and cyclic voltammetry. The result gives a surprising evidence for intercalation of DNA by the negatively charged complex species containing non typical intercalating ligands with Kb of order 104 M−1. Na[RuCl2(N-R-5-X-salim)2], where R represents butyl or phenyl and X = H, Cl, were characterized on the basis of elemental analysis, MALDI-TOF mass spectrometry, infrared, UV / visible spectroscopic measurements and cyclic voltammetry. (doi: 10.5562/cca2216

Electrochemical Determination of Adrenaline at Ru(III) Schiff Base Complex Modified Carbon Electrodes

The anodic oxidation of adrenaline on ruthenium(III) Schiff base complex modified carbon electrodes was used for determination of adrenaline by flow-injection analysis, cyclic voltammetry, differential pulse voltammetry and hydrodynamic amperometry. The electrocatalytic properties of ruthenium(III) complex at glassy and screen printed carbon electrodes were enhanced by addition of cellulose acetate and multi-walled carbon nanotubes. Flow injection amperometric measurements were performed at 100 mV vs. Ag / AgCl in 0.1 M phosphate buffer pH 7.5 at 0.4 mL min−1 flow rate. Novel sensor provided a linear dynamic range up to 50 mg L−1 of adrenaline with detection limit of 53 µg L−1 at physiological pH. Determination of adrenaline in commercial sample was carried out by flow-injection method with excellent recoveries 99.8–101 %. This work is licensed under a Creative Commons Attribution 4.0 International License

Chalcone and Flavonol Copper(II) Complexes Containing Schiff Base Co-Ligand: Synthesis, Crystal Structures and Catecholase-like Activity

Four new heteroleptic copper(II) complexes having chalcone or flavonol ligands and Schiff base (N-phenyl-5-chlorosalicylideneimine) as co-ligand were prepared, chemically and structurally characterized and investigated as functional biomimetic catecholase models. The complexes were prepared by the solution synthesis and crystal and molecular structures were determined by X-ray diffraction. Complexes were chemically characterized by elemental analysis, infrared and electronic absorption spectroscopy as well as by electrochemical measurements. Copper(II) chalcone complexes, with square-pyramidal CuO4N core, are binuclear, featuring phenolate oxygen from the Schiff base as a bridging atom, while copper(II) flavonol complexes are mononuclear, and reveal a square planar CuO3N coordination core. Catalytic activity of the complexes in 3, 5-di-tert-butylcatechol oxidation was confirmed by spectrophotometric and electrochemical measurements. Kinetic measurements revealed that the binuclear (chalcone-containing) complexes have enhanced catalytic activity as compared to the mononuclear Cu(II) flavonol complexes. Relatively high kcat values (300 – 750 h–1) confirmed their respectable biomimetic catecholase-like activity

UNEMPLOYMENT AS FACTOR QUALITY OF LIFE

Brezposelnost je eden najresnejših družbenih problemov. Med brezposelnimi se nahajajo osebe različnih poklicev in znanj: od nekvalificiranih delavcev do delavcev z visokim strokovnim znanjem, tistih, ki imajo deset, dvajset in več let delovne dobe in izkušenj, in so postali tako imenovani trajni presežek in tisti, ki so šolanje šele zaključili in iščejo svojo prvo zaposlitev. Brezposelnost je postala splošno razširjen in množičen pojav. Na izbiro teme za diplomsko nalogo z naslovom Brezposelnost kot faktor kvalitete življenja je vplivala moja brezposelnost. V prvem delu sem se osredotočila na kvaliteto življenja, zdravje, prosti čas, stanovanje, izobraževanje, teoretična spoznanja o brezposelnosti, kako brezposelnost vpliva na posameznika in kakšna je kvaliteta življenja brezposelnih. Za izdelavo naloge sem uporabila različna gradiva: ZRSZ, primerjavo statističnih podatkov o brezposelnosti v Sloveniji od leta 2005 do julija 2009 na sploh in statistične podatke v občini Ilirska Bistrica. V drugem delu sem uporabila anketo, ki so jo prijavljeni brezposelni izpolnjevali na uradu za delo v Ilirski Bistrici. Po obdelavi podatkov v anketi sem rezultate predstavila v obliki tabel in grafov.Unemployment is the one of the most serious social problems. Among unemployed are person of differend professions and skills: from unskilled workers to workes with high experience, those who have ten, twenty years of service and experience and have become so-colled permanent surplus and those who have just completed their schooling and are seeking their first job. Unemployed has become a widespread and massive appearance. The selecting subject for the diploma thesis entitled Unemployment as a factor of quality of life is affecting my unemployment. In the first part I focus on quality of life, health, leisure, housing, education, theoretical knowledge about unemployment, how unemployment affects the individual and what s the quality of life of the unemployed. For the production tasks, I use different materials: Institute of the Republic of Slovenia for employmen, a comporision of statistics data on unemployment in Slovenia from 2005 to July 2009 in general and statistics in the municipality in Ilirska Bistrica. In the second part I used a survey that I conducted at the office to work in the Ilirska Bistrica, where they complete registered unemployed. After processing the data receive in a survey I present the results in the form of tables and gruphs

CT DNA, BSA and Antiproliferative Activity of Ru(II) Bipyridine Complexes Containing Schiff Bases Derived from Amino Acids

Complexes of general formula [Ru(bpy)2(L)]CF3SO3, where bpy = 2,2′-bipyridine, and L = Schiff bases derived from salicylaldehyde and amino acids (glycine (1a), cysteine (1b), methionine (1c) and phenylalanine (1d)) were synthesized. Characterization based on elemental analysis, Ru content, mass, infrared and electronic spectra confirmed RuN5O coordination unlike 1b where coordination occurred via azomethine nitrogen and cysteine sulfur. Cyclic voltammograms, except 1b, showed several quasi-reversible redox pairs in the positive potential range, the first located at about 0.5 V, corresponding to similar heteroleptic Ru(II) bipyridyl complexes. Biological activity was tested by interactions with DNA and BSA. DNA binding constants of order 103 M−1, suggest groove binding due to bpy ligand and hydrogen bonding of the OH and CO groups from the imine moiety. In vitro BSA protein inhibition assay performed by spectrofluorimetry showed Complex : BSA binding in 1 : 1 ratio with Kb of 104 M−1 order. Cytotoxicity studies by MTT assay for 72 h of drug action revealed activity of 1a and 1d against breast cancer MCF-7 cells with IC50 values 32 ± 8 and 26 ± 1µM, respectively

<i>In vitro</i> anticancer activity of binuclear Ru(II) complexes with Schiff bases derived from 5-substituted salicylaldehyde and 2-aminopyridine with notably low IC₅₀ values

<p>The binuclear Ru(II) complexes with Schiff bases derived from 5-chlorosalicyladehyde and 2-aminopyridine and its 5-substituted salicylideneimine homologues were tested <i>in vitro</i> against cervical carcinoma (HeLa), metastatic colorectal adenocarcinoma (SW620), lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and human lung fibroblast (WI-38) cell lines. All compounds showed strong antiproliferative activity with extremely low IC₅₀ values. The compounds expressed strong activity against gram-positive bacteria, <i>Staphylococcus aureus</i> and <i>Enterococcus faecalis</i>.</p

Heteroleptic ruthenium bioflavonoid complexes: from synthesis to <i>in vitro</i> biological activity

<p>Heteroleptic ruthenium(II) bioflavonoid complexes of quercetin, morin, chrysin, and 3-hydroxyflavone were prepared and their interaction with CT DNA and BSA along with antioxidant and <i>in vitro</i> anticancer and antimicrobial activities was investigated. The formulation and characterization of complexes were achieved through elemental and thermal analysis, mass spectrometry, ¹H NMR spectroscopy along with infrared, electronic absorption, and emission spectroscopy as well as square-wave voltammetry, and magnetic and conductivity measurements. Ruthenium(II) is octahedrally coordinated in cationic complex species to two bidentate diimine ligands (2,2′-bipyridine or 1,10-phenanthroline) and one bidentate monobasic flavonoid ligand through 3,4-site of quercetin, morin, and 3-hydroxyflavone or 4,5-site of chrysin. Complexes bind CT DNA by intercalation and binding constants comparable to ethidium bromide or 10 times higher. Binding constants of complexes to BSA were several times higher compared to ibuprofen and diazepam, and suggest that the complexes have a strong affinity to BSA. Antioxidant activity tests showed that the complexes are more potent in terms of radical inhibition compared to the parent flavonoids. Cytotoxic testing revealed that the Ru(II) complex of quercetin with 2,2′-bipyridine co-ligand has good selectivity to breast adenocarcinoma, while the complex of 3-hydroxyflavone with 2,2′-bipyridine co-ligand showed strong cytotoxicity toward all tested cell lines with IC₅₀ ∼ 1 μM. All complexes showed moderate activity toward <i>Acinetobacter baumannii</i>, while the Ru(II) complex of 3-hydroxyflavone with 2,2′-bipyridine showed excellent activity toward MRSA and <i>Candida albicans</i>.</p