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排序方式: 共有163条查询结果,搜索用时 15 毫秒
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Lina Hudhud David R. Chisholm Andrew Whiting Anita Steib Krisztina Pohczky Angla Kecsks va Szke Zsuzsanna Helyes 《Molecules (Basel, Switzerland)》2022,27(3)
All-trans-retinoic acid (ATRA), the active metabolite of vitamin A, plays a pivotal role in cell differentiation, proliferation and embryonic development. It is an effective therapy for dermatological disorders and malignancies. ATRA is prone to isomerization and oxidation, which can affect its activity and selectivity. Novel diphenylacetylene-based ATRA analogues with increased stability can help to overcome these problems and may offer significant potential as therapeutics for a variety of cancers and neurodegenerative diseases, including amyotrophic lateral sclerosis. Here, we investigated the effects of these retinoids on cell viability and genotoxicity in the widely used model system of the rapidly proliferating Chinese hamster ovary cell line. DC360 is a fluorescent ATRA analogue and DC324 is a non-active derivative of DC360. EC23, DC525, DC540, DC645, and DC712 are promising analogues with increased bioactivity. The cytotoxic activity of the compounds was evaluated by ATP assay and DNA damage was tested by comet assay. No cytotoxicity was observed in the 10−6–10−5 M concentration range. All compounds induced DNA migration similar to ATRA, but DC324, DC360 and EC23 did so to a greater extent, particularly at higher concentrations. We believe that retinoid receptor-independent genotoxicity is a general characteristic of these compounds; however, further studies are needed to identify the molecular mechanisms and understand their complex biological functions. 相似文献
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Tüdos E Fiser A Simon A Dosztányi Z Fuxreiter M Magyar C Simon I 《Journal of chemical information and computer sciences》2004,44(2):347-351
Proteins are heteropolymers with evolutionary selected native sequences of residues. These native sequences code for unique and stable 3D structures indispensable for biochemical activity and for proteolysis resistance, the latter which guarantees an appropriate lifetime for the protein in the protease rich cellular environment. Cross-links between residues close in space but far in the primary structure are required to maintain the folded structure of proteins. Some of these cross-links are covalent, most frequently disulfide bonds, but the majority of the cross-links are sets of cooperative noncovalent long-range interactions. In this paper we focus on special clusters of noncovalent long-range interactions: the Stabilization Centers (SCs). The relation between the SCs and secondary structural elements as well as the relation between SCs and functionally important regions of proteins are presented to show a detailed picture of these clusters, which are believed to be primarily responsible for major aspects of protein stability. 相似文献
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Ferenc Sóti Mária Incze Zsuzsanna Kardos-Balogh Maária Kajtár-Peredy Csaba Szántay 《合成通讯》2013,43(12):1689-1698
7-Methoxytryptamine (6a) was prepared from cheap and easily available starting materials by using the Abramovitch-Shapiro method. 相似文献
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Triacetone-triperoxide is a high explosive mainly used by terrorist groups. With the spreading of the recipe on the Internet, increasing number of bomb attacks are being reported worldwide using triacetone-triperoxide. A simple identification method is described using 100 μm polydimethyl siloxane fibre solid phase microextraction and gas chromatography combined with spectrometry. The method was tested on various pre- and post-explosion models that can be collected in a house search or after a bomb attack. Sample preservation and stability was also examined. Identification of triacetone-triperoxide residues in post-explosion models was feasible 24 h after ignition, the detection limit being 5 ng. 相似文献
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Three online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method examples are presented where two different types of chromatographic columns or solvent systems were coupled to meet specific analytical objectives: (i) SPE of target analytes by restricted access media from high ionic strength urine matrix was coupled with reversed phase LC-MS/MS conditions accommodating high ionization potentials of the analytes (urinary bisphenol A and other phenolic derivatives); (ii) strong cation exchange SPE of analytes of diverse polarity and pK(a) was coupled with reversed phase LC-MS/MS analysis (urinary atrazine metabolites); (iii) pre-concentration of low pg per sample analytes by weak anion exchange SPE was hyphenated with ion pair LC-MS analysis (intracellular nucleotide triphosphate analogs). With these examples we suggest a conductive generic work flow for the development of online SPE-LC-MS methods and show how advanced commercial LC devices and software allow for the design of complex yet highly versatile analytical separation systems suited to the unique physicochemical properties of the target analytes. 相似文献
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Pál Tapolcsányi Bert U.W Maes Katrien MonsieursGuy L.F Lemière Zsuzsanna RiedlGyörgy Hajós Bart Van den DriesscheRoger A Dommisse Péter Mátyus 《Tetrahedron》2003,59(31):5919-5926
Palladium-catalyzed intramolecular arylation of 2-benzyl-5-(2-bromophenyl)-4-phenylpyridazin-3(2H)-one yielded hitherto unknown 2-benzyldibenzo[f,h]phthalazin-1(2H)-one. The synthesis of this new tetracyclic pyridazinone from 2-benzyl-5-(2-aminophenyl)-4-phenylpyridazin-3(2H)-one via a Pschorr type reaction was also investigated. Similarly, the construction of 2-methyldibenzo[f,h]cinnolin-3(2H)-one from 2-methyl-5-(2-bromophenyl)-6-phenylpyridazin-3(2H)-one and 2-methyl-5-(2-aminophenyl)-6-phenylpyridazin-3(2H)-one is also reported. Removal of the N-benzyl protective group of 2-benzyl-dibenzo[f,h]phthalazin-1(2H)-one with AlCl3 yielded unsubstituted dibenzo[f,h]phthalazin-1(2H)-one. 相似文献
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Gaál V Kilár F Acs B Szijjártó Z Kocsis B Kustos I 《Colloids and surfaces. B, Biointerfaces》2005,45(3-4):125-130
Implantation of artificial intraocular lenses into the eye during ophthalmic surgical procedures ensures an unliving surface on which bacterial pathogens may attach and form biofilms. Despite antibiotic treatment bacteria growing in biofilms might cause inflammation and serious complications. In this study the adhesive ability of 7 Staphylococcus aureus and 11 coagulase-negative Staphylococcus (CNS) strains to the surface of acrylic intraocular lenses had been examined by the ultrasonic method. In untreated cases adhesion of the S. aureus and CNS strains did not differ significantly. We could not demonstrate significant differences between the adhesive ability of the standard strains and the clinical isolates. In this study a single – 60 min long – antibiotic (ciprofloxacin and tobramycin) treatment had been applied, that correlate well with the single or intermittant antibiotic prophylaxis of patients. Ciprofloxacin administration was able to reduce significantly the number of attached cells on the surface of acrylic lenses both in the case of S. aureus and CNS strains. Dependence of the effect from concentration could also be demonstrated. Tobramycin treatment was able to inhibit significantly the attachment of S. aureus cells. Despite the debate on antibiotic prophylaxis we presented in our experiments that a single antibiotic administration can decrease the attachment of bacterial cells to the surface of acrylic intraocular lenses, and might be effective in the prevention of postoperative endophthalmitis, that is a rare but serious complication of ophthalmic surgery. 相似文献