Synthesis and MALDI-TOF-MS of PS-PMA and PMA-PS block copolymers

The synthesis of well-defined block copolymers from styrene and methyl acrylate via ATRP is discussed in this contribution. Kinetic studies on these block copolymerizations as well as characterization studies were performed to investigate the monomer composition in the respective PS and PMA blocks. MALDI-TOF-MS was performed to clarify the exact number of repeating units of each block and the total number of units in the block copolymer. Block copolymers up to 22 kDa could be analyzed by MALDI-TOF-MS, whereby polymers with PMA as first block showed a large second distribution corresponding to PMA homopolymers. However, SEC demonstrated that only a small amount of homopolymer was present indicating that care needs to be taken with interpreting MALDI-TOF-MS data, which is a qualitative rather than a quantitative technique.     

99mTc-labelled human serum albumin: Chemical and electrochemical labelling methods

The labelling of human serum albumin /HSA/ with^99mTc has been investigated using a chemical method /stannous citrate/ and electrolytically generated tin/II/ ions. A comparative study of various chemical parameters and current intensities has been carried out in order to find the optimal conditions for labelling. The labelling yield was over 95%, for the chemical and electrolytical methods.     

Composition,properties, and application of products formed in oxidation of polyethylene by nitric acid

Structure of products formed in polyethylene oxidation by nitric acid was studied by NMR, IR, and electronic absorption spectroscopies and derivatography.     

Titrimetric determination of selenium in anodic slimes

The determination of selenium in the presence of tellurium and copper has been studied, to allow analysis of anodic slimes from electrolytic copper refining. Three methods have been developed for the determination of selenium in these slimes. They are based on the extraction of selenium with sodium sulphite, reduction of selenite with sodium sulphite, and separation of selenium and tellurium by adjustment of pH. Selenium (10(-3)-10(-2)M) is determined in the presence of tellurium, copper, iron, silver and lead. The methods are fast and simple, do not need expensive reagents, and give satisfactory results.     

Pharmacological properties of dicyanidoaurate(I)-based complexes: characterization and single crystal X-ray analysis

The synthesis of three bimetallic cyanido complexes with edbea [2,2′-(ethylenedioxy)bis(ethylamine)] ligand is reported. [Ni^II(μ-edbea)₂{Au(μ-CN)₂}₂]_n (1), [{Cu^II(edbea)}₂{Au(μ-CN)₂}₄]_n (2) and [Cd^II(edbea)₂][Au(CN)₂]₂·H₂O (3) were fully characterized by elemental, infrared, XRD (3), ESI-MS and thermal analysis. The DNA/BSA binding properties of these complexes were evaluated by spectrophotometric titration, fluorometric ethidium bromide kinetics, and DNA electrophoresis studies and their partially minor groove binding mode between the base pairs of DNA and electrostatic interaction between the amino acid residues of BSA were explained. The complexes were tested for their pharmacological properties. These molecules had excellent in vitro antiproliferative activity and also exhibited a strong tumor inhibiting effect against HT29, HeLa, C6 and Vero cell lines. These complexes had metastatic features as they are able to reduce cell migration activity and suppress tumor growth in vitro. Analysis of the DNA topoisomerase I relaxing activity indicates that the complexes do not inhibit topoisomerase I which regulates the topological states of the DNA double helix during DNA processing reactions. The TUNEL and DNA laddering assay results indicated that these compounds may destroy cell maintenance by triggering apoptosis. Immunohistochemistry staining analysis demonstrated that these complexes significantly decreased the expression of Bcl-2 in HeLa and HT29 cells while increasing the expression of P53 levels. Overall, the potent antiproliferative activity, low cytotoxic effect, good solubility, and micro molar range dosage observed for these complexes emphasizes their potential as anticancer drug candidates.     

1,2-Bis-(2-benzimidazolyl)-1,2-ethanediol and 1,4-bis-(2-benzimidazolyl)-1,2,3,4-butanetetraol PdCl2 complexes

The 1,2-bis-(2-benzimidazolyl)-1,2-ethanediol (EH₂) and 1,4-bis-(2-benzimidazolyl)-1,2,3,4-butanetetraol (TH₄) ligands form 4-coordinate mono- and bi-metallic complexes with PdCl₂, respectively. In Pd(EH₂)Cl₂ the ligand acts as a bidentate through two of the nitrogen atoms. On the other hand, in Pd₂(TH₄)Cl₄ the ligand coordinates to two palladium atoms through both bis-benzimidazole nitrogen atoms and two oxygen atoms of the hydroxy groups, forming two different isomers. The complexes were characterised by analytical data, magnetic susceptibility, molar conductivity, and also by i.r., ¹H- and ¹³C-n.m.r. spectra.     

Hazardous metal geochemistry of sedimentary phosphate rock used for fertilizer (Maz?dag, SE Anatolia, Turkey)

Composition of phosphate rocks mostly depend on their type and origin. Sedimentary rocks contain high concentration of heavy metals. Phosphate rocks are mainly used for the manufacturing of phosphate fertilizers. The contents of heavy metals Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn, as well as rare earth elements Ce, La, and Th were determined in sedimentary phosphate rock used for production of fertilizer in Turkey. The Kasrik-Semikan, Mazidag (Mardin, SE Anatolia, Turkey) high-grade phosphate rock used in this study is situated near the border with Syria and was deposited during the Turonian and Senonian (Cretaceous) ages. Total phosphorus (P) concentration in the rock is 18.5% on the average. Microwave acid digestion (MW-AD) followed by ?nductively Coupled Plasma-Optical Emission Spectrophotometry (ICP-OES) was carried out for the determination of all the elements of interest in phosphate rock. The results revealed that hazardous metal content of the phosphate rock was lower in Mazidag phosphate than that in samples imported from other countries and were within the safety limits.     

Spectral characterization and antibacterial effect of 2-methyl-6-(5-H-Me-Cl-NO <Subscript>2</Subscript>-1<Emphasis Type=Italic>H</Emphasis>-benzimidazol-2-yl)-phenols and some transition metal complexes

2-Methyl-6-(5-H-methyl-chloro-nitro-1H-benzimidazol-2-yl)-phenols( HL _x :x= 1-4)ligands and HL₁ complexes with Fe(NO₃)₃, Cu(NO₃)₂, AgNO₃, Zn(NO₃)₂ have been synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis, molar conductivity, magnetic moment, FT-IR, ¹H-and ¹³C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimum inhibitory concentration dilution method, against nine bacteria. While HL₁ ligand has not any activity, it’s Ag(I) complex show antibacterial effect toward almost to all the bacteria. Zn(II) complex has antibacterial effect on especially K. pneumoniae, S. epidermidis and S. aureus bacteria.