Search results for "Pyrene"
showing 10 items of 260 documents
Hyperbranched polyethylenimines as versatile precursors for the preparation of different type of unimolecular micelles
2007
Abstract Hyperbranched polyethylenimine (HPEI) was successfully employed as precursor for the preparation of unimolecular inverted and aqueous micelles. The unimolecular inverted micelles (UIMs) obtained by the amidation of HPEI with 1,1′-carbonyldiimidazole (CDI) activated palmitic acid exhibited high encapsulation efficiency for hydrophilic anionic dyes and the efficiency could be enhanced significantly by decreasing the degree of amidation or quaternizing the residual amines. The weight ratio of loaded guests to the amidated HPEIs was not dependent on the molecular weight of HPEI core when the degree of amidation was kept constant. Decreasing the length of the aliphatic chain from 16 to …
Pyrene Containing Polymers for the Non-Covalent Functionalization of Carbon Nanotubes
2009
Pyrene containing diblock copolymers based on poly(methyl methacrylate) were synthesized and investigated regarding their adsorption on carbon nanotubes (CNT). The pyrene units were introduced using a reactive ester monomer for the build up of the second block which later on was reacted polymer-analogously with amine functionalized pyrene derivatives. As we started from the same reactive ester intermediate, full block length identity is given. We varied the length of the anchor block to find an optimal block length and used pyren-1-yl-methylamine as well as 4-pyren-1-yl-butylamine as anchor units. For both anchor units a maximal adsorption was found for 13 and 20 anchor units, respectively.…
Stereoselective Metabolic Activation of Dibenzo[a,l]Pyrene in the Human Mammary Carcinoma Cell Line MCF-7 Results in Formation of (-)-antiand (+)-syn…
1996
Abstract Dibenzo[a,l]pyrene (DB[a,l]P) is an important polycyclic aromatic hydrocarbon because of possible human exposure and its exceptionally high carcinogenicity in rodents. We examined the metabolism of DB[a,l]P and the formation of DB[a,l]P-DNA adducts in the human mammary carcinoma cell line (MCF-7). Analysis of the DNA adducts by 33P-postlabeling, immobilized boronate chromatography, HPLC and TLC demonstrated that DB[a,l]P is stereoselectively metabolized to specific optical isomers of DB[a,l]P-11,12-diol-13,14-epoxide (DB[a,l]PDE). The major anti-DB[a,l]PDE adduct formed in DB[a,l]P-treated MCF-7 cells resulted from reaction of (-)-anti-DB[a,l]PDE with DNA whereas the two major syn-…
Dual removal and selective recovery of phosphate and an organophosphorus pesticide from water by a Zr-based metal-organic framework
2021
The authors express their thanks for the financial support provided by the Marie Sklodowska-Curie Individual Fellowships (H2020-MSCA-IF-2019-EF-ST-888972-PSustMOF, F.J.C.; H2020-MSCA-IF-2016-GF-749359-EnanSET, N.M.P.) within the European Union H2020 programme and EU FEDER. MINECO (CTQ2017-84692-R, PID2020-113608RB-I00, PEJ2018-004022-A), Universidad de Granada (Plan Propio de Investigacion and Programa Operativo FEDER Andalucia 2014-2020: B-FQM-364-UGR18), Junta de Andalucia (P18-RT-612) and 2020 Post-doctoral Junior Leadere-Retaining Fellowship, la Caixa Foundation (ID 100010434 and fellowship code LCF/BQ/PR20/11770014, N.M.P.) are also acknowledged for funding. Funding for open access cha…
Spectroscopic Studies of Oligonucleotide Adducts and Base Sequence Preference of Adducts Formed by the Stereoisomers of 7,8-Dihydroxy-9,10-epoxy-7,8,…
1996
Abstract 5′-d(CCTATAGATATCC) has been reacted with BPDE and the adducts derived from binding of BPDE to the exocyclic amino group of deoxyguanosine (dG) were studied with spectroscopic methods. The major dG-adducts of (+)- and (-)-anti-BPDE and a minor adduct of (+)-syn-BPDE showed the characteristics of trans-adducts. The major products formed with (+)- and (-)-syn-BPDE exhibit cis-adduct characteristics. Annealing of BPDE-modified oligonucleotides to complementary or partially complementary strands results in reduced fluorescence intensity in several cases and in others the intensity is markedly increased. These differences demonstrate that the adduct microenvironment is strongly influenc…
Correlation of the Extent of Fjord-Region Oxidation with DNA Binding and Mutagenicity of the Enantiomeric 11,12-Dihydrodiols of Dibenzo[a,l]pyrene
1996
Abstract In vitro studies on the hepatic biotransformation of the enantiomeric trans-11,12-dihydrodiols of dibenzo[a,l]pyrene (DB[a,l]P) using microsomal fractions of animals pretreated with Aroclor 1254 revealed that the formation of fjord-region dihydrodiol epoxides strongly depends on the absolute configuration of the substrate. Both the (-)-11R,12R- and the (+)-11S,12S-enantiomer are converted diastereoselectively to the (-)- and (+)-anti-dihydrodiol epoxide, respectively, by either rat or mouse liver microsomes. Fjord-region oxidation occurs to greatest extent on incubation of the (-)-11R,12R-dihydrodiol with preparations from rats. This finding is in line with the differences seen for…
Response of rainbow trout transcriptome to model chemical contaminants.
2004
We used high-density cDNA microarray in studies of responses of rainbow trout fry at sublethal ranges of beta-naphthoflavone, cadmium, carbon tetrachloride, and pyrene. The differentially expressed genes were grouped by the functional categories of Gene Ontology. Significantly different response to the studied compounds was shown by a number of classes, such as cell cycle, apoptosis, signal transduction, oxidative stress, subcellular and extracellular structures, protein biosynthesis, and modification. Cluster analysis separated responses to the contaminants at low and medium doses, whereas at high levels the adaptive reactions were masked with general unspecific response to toxicity. We fo…
Retene, pyrene and phenanthrene cause distinct molecular-level changes in the cardiac tissue of rainbow trout (Oncorhynchus mykiss) larvae, Part 2 – …
2020
Polycyclic aromatic hydrocarbons (PAHs) are global contaminants of concern. Despite several decades of research, their mechanisms of toxicity are not very well understood. Early life stages of fish are particularly sensitive with the developing cardiac tissue being a main target of PAHs toxicity. The mechanisms of cardiotoxicity of the three widespread model polycyclic aromatic hydrocarbons (PAHs) retene, pyrene and phenanthrene were explored in rainbow trout (Oncorhynchus mykiss) early life stages. Newly hatched larvae were exposed to sublethal doses of each individual PAH causing no detectable morphometric alterations. Changes in the cardiac proteome and metabolome were assessed after 7 o…
CD40 ligation protects bronchial epithelium against oxidant-induced caspase-independent cell death.
2006
KEYWORDS CLASSIFICATION: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide;Antigens,CD40;Apoptosis;Bronchi;cytology;Caspases;Cell Cycle;Cell Death;Cell Line,Transformed;Cell Survival;Cell Transformation,Viral;Cytoprotection;drug effects;Epithelial Cells;Humans;Italy;mechanisms of carcinogenesis;metabolism;Oxidants;pharmacology;physiology;Research;Simian virus 40;toxicity;Transcription Factor AP-1. CD40 and its ligand regulate pleiotropic biological responses, including cell proliferation, differentiation, and apoptosis. In many inflammatory lung diseases, tissue damage by environmental or endogenous oxidants plays a major role in disease pathogenesis. As the epithelial barrier is a major t…
On the Use of Metal Purine Derivatives (M=Ir, Rh) for the Selective Labeling of Nucleosides and Nucleotides
2014
The reactions of neutral or cationic IrIII and RhIII derivatives of phenyl purine nucleobases with unsymmetrical alkynes produce new metallacycles in a predictable manner, which allows for the incorporation of either photoactive (anthracene or pyrene) or electroactive (ferrocene) labels in the nucleotide or nucleoside moiety. The reported methodology (metalation of the purine derivative and subsequent marker insertion) could be used for the postfunctionalization and unambiguous labeling of oligonucleotides.