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141.
Andrii Lozynskyi Borys Zimenkovsky Iryna Ivasechko Julia Senkiv Andrzej Gzella Olexandr Karpenko 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):1149-1157
AbstractThe synthesis and anticancer activity evaluation of new thiazolo[4,5-b]pyridine-5-carboxylic acid amides is described. The structures of the synthesized compounds were confirmed by spectroscopic data and a single crystal X-ray diffraction analysis for 2.4. The synthesized compounds were screened for their in vitro anticancer activity according to US NCI protocols. The most active 7-(4-fluorophenyl)-2-oxo-2,3-dihydrothiazolo[4,5-b]pyridine-5-carboxylic acid (4-chlorophenyl)amide 2.2 and 7-(4-chlorophenyl)-2-oxo-2,3-dihydrothiazolo[4,5-b]pyridine-5-carboxylic acid (4-chlorophenyl)amide 2.5 were screened for their cytotoxicity effects on C6 Rat glioma cells and U373 Human glioblastoma astrocytoma cells which revealed promising results comparable to temozolamide as reference control according MTT assay data. 相似文献
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Andrzej Okruszek Mandalena Olesiak Wojciech J. Stec 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Nucleoside 3′-0- and 5′-O-phosphorodithioates have been recently described by Caruthers et al.1 as a new type of nucleotide analogues. These compounds have also been obtained in our Laboratory by one-pot dithiaphospholane approach.2 We now report on the transformation of some of these derivatives into new class of dinucleotide analogues. We have found that nucleoside 3′-O-phosphorodithioates (1) react in DMF solution with 5′-bromo-5′-deoxythymidine to give in high yield corresponding dinucleoside (5′→3′)-O,S-phosphorodithioates (2) - first examples of a new class of dinucleotide analogues possessing the internucleotide phosphorothioate linkage with one of the sulfur atoms in a 3′-bridging position. 相似文献
146.
Abstract Conformational behaviour of about 30 2-methoxy-2-oxo-1,2- oxaphospho l an-3-0 1 s containing various substituents was examined by 1H and 13C NMR. Vicinal coupling constants J(HCCH), J(HCCP), J(HCOP), J(CCOP) and J(CCCP) were employed in this study. Conformation of the 1,2-oxaphospholane ring is governed almost exclusively by substituents at C-3, C-4 and C-5, as we l l as by their orientation. The configuration of the P atom has little or no influence on conformation of the ring in diastsreomeric pairs. Strong preference of phenyl, methyl and substituted methyl groups to occupy the equatorial or pseudoequatoria l positions was observed for all but one compounds studied. In the cis-fused bicyclic syst ems conformat ionally rigid 6-membered rings forced the 1,2-oxaphospholane rings to adopt an enve l ope-l ike (E4) conformation. No influence of the p=o……HO-C-3 hydrogen bond on conformation of the 1,2-oxaphospholane ring was found. Preferred conformations for (2R, 3R, 4R)-3-(hydroxymethyI)-2-methoxy-2-oxo-1,2-oxaphospho lane-3,4-diol and its triacetate are shown below. 相似文献
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148.
Roza Trzcinska Piotr Suder Anna Bodzon-Kulakowska Magdalena Skalska Andrzej Marcinkowski Jerzy Kubacki Roman Pedrys Jerzy Silberring Andrzej Dworak Barbara Trzebicka 《Analytical and bioanalytical chemistry》2013,405(28):9049-9059
Peptide surfaces were obtained by the covalent immobilisation of fluorescently labelled pentapeptides carboxyfluorescein–glycine–arginine–methionine–leucine–glycine, either directly or through a poly(ethylene glycol) (PEG) linker on modified silicon wafers. Each step during the preparation of the peptide surfaces was confirmed by several surface characterisation techniques. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy were used to determine the surface composition, the wafers philicity was measured by contact angle and atomic force microscopy was used to investigate the surface morphology. Exposure of the peptide surfaces to trypsin resulted in the release of a fluorescently labelled peptide product, which allowed the kinetics of the enzymatic reaction to be followed with the aid of fluorescence spectroscopy. The electrospray ionisation mass spectrometry analysis of the post-digestion solution confirmed that the pentapeptides attached to the solid support undergo specific trypsin hydrolysis at the C-terminus of the arginine residues. Detailed surface analyses before and after the enzyme action was performed using ToF-SIMS. Because of the limited accessibility of the short peptide directly attached to the surface, a quantitative yield of enzymatic hydrolysis was observed only in case when the peptide was bound through the PEG linker. The insertion of the PEG linker increased the number of immobilised peptides and the rate of enzymatic digestion which consequently improved the quality of the enzyme assays. The described approach may be used for different peptide sequences designed for other proteases. Figure
Monitoring of trypsin hydrolysis on PEG-peptide surface 相似文献
149.
Marzena Dabioch Robert Skorek Andrzej Kita Piotr Janoska Katarzyna Pytlakowska Piotr Zerzucha Rafal Sitko 《Central European Journal of Chemistry》2013,11(5):742-753
Elements that enter the aquatic environment may pose a health risk to wildlife and humans. The aims of this study were: to determine how the introduction of activated carbon for a water purification system will improve the quality of the water produced; and to investigate the sorption of metals on activated carbons, including determination of the accumulation, as well as changes in concentrations of elements in carbons. The tests were carried out on three types of activated carbons with different granular structure. All samples were collected from Water Treatment Plant Goczalkowice, Poland. Concentrations of elements were measured using an optical emission spectrometer with inductively coupled plasma. The experiment showed that metals accumulating in the activated carbons during the operation included: Ca, Mn, Zn, and Cu. In each of the three types of carbons, it can distinguish such elements as Ba, Al, Cr, Ni, Ti, which are characterized by irregular accumulation during the operation of the filter. The introduction of carbon sorbent for water treatment largely contributed to improvement in the quality of raw material supplied to customers, mainly with regard to taste and smell, as well as to reduction of basic parameters: color, absorbance in the UV range and oxidability. 相似文献
150.
Andrzej Okuniewski Jaroslaw Chojnacki Katarzyna Baranowska Barbara Becker 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(2):195-198
Two new dialkylammonium thiosulfates, namely bis(diisopropylammonium) thiosulfate, 2C6H16N+·S2O32−, (I), and bis(tert‐butylammonium) thiosulfate, 2C4H12N+·S2O32−, (II), have been characterized. The secondary ammonium salt (I) crystallizes with Z = 4, while the primary ammonium salt (II), with more hydrogen‐bond donors, crystallizes with Z = 8 and a noncrystallographic centre of inversion. In both salts, the organic cations and thiosulfate anions are linked within extensive N—H...O and N—H...S hydrogen‐bond networks, forming extended two‐dimensional layers. Layers are parallel to (10) in (I) and to (002) in (II), and have a polar interior and a nonpolar hydrocarbon exterior. The layered structure and hydrogen‐bond motifs observed in (I) and (II) are similar to those in related ammonium sulfates. 相似文献