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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Synthesis of some compounds of possible carcinogenic activity

Borkovec, Alexej B. 12 January 2010 (has links)
1. The acid catalyzed cyclodehydration method was extended to the 9-aryl-1,2-benzanthracene and 9-naphthylanthracene series. 2. A new method of cyeclodehydration was described. 3. The series of 10-mono- and 10-dimethylphenyl-1,2-benzanthracenes was completed. All the isomeric 9-mono- and 9-dimethylphenyl-1,2-benzanthracenes were prepared together with the corresponding ketones. Some highly hindered ketones were prepared and their cyclization realized. A total of 47 compounds, not previously reported in the literature, were synthesized. 4. The spectra of 24 hydrocarbons were recorded and the theory of nonplanarity of these compounds substantiated. / Ph. D.
12

A Review of Perfluorooctanoic Acid Carcinogenicity and Application to Human Risk

Stone, Kenneth Lee 20 July 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Perfluorooctanoic acid (PFOA) is a synthetic organic chemical that consists of an 8 carbon alkyl chain with a terminal carboxyl group in which the carbon-hydrogen bonds have been replaced with carbon-fluorine bonds except at the terminal carboxyl end. This perfluoralkyl carboxylate is a contemporary synthetic chemical that does not occur naturally in the environment and has only seen widespread use within the last 50 years. PFOA is environmentally persistent and is ubiquitously found in human serum. PFOA has been shown to induce a tumor triad consisting of liver adenomas, Leydig cell adenomas and pancreatic acinar cell tumors in male Spraque-Dawley rats. The ability of PFOA to produce tumors in rodents compounded by the fact that PFOA is accumulating not only in those occupationally exposed, but also in the general population, justifies concern about the carcinogenic potential of PFOA in humans. This paper reviews the data from current published research and reveals that some carcinogenic pathways identified in the tumors produced by PFOA in experimental animals may provide a plausible mode of action for human carcinogenesis.
13

Synthesis, biological evaluation and molecular docking studies of novel indole- and benzofuran-chalcone and benzofuran-quinazoline hybrids as anticancer agents

Maluleka, Marole Maria 07 1900 (has links)
Text in English / Specially prepared 2-amino-5-bromo-3-iodoacetophenone and 5-bromo-2-hydroxy-3 iodoacetophenone were subjected to Claisen-Schmidt aldol condensation with benzaldehyde derivatives followed by sequential and/or one-pot palladium catalyzed Sonogashira cross coupling and heteroannulation of the 3-alkynylated intermediates to afford indole-chalcones and benzofuran-chalcones, respectively. The indole-chalcones derivatives were, in turn, subjected to trifluoroacetic anhydride in tetrahydrofuran under reflux to afford the corresponding 3-trifluoroacetyl substituted indole-chalcone derivatives. The coupling constant values (Jtrans) of about 16.0 Hz for the chalcone derivatives corresponding to the vinylic protons confirmed the trans geometry of the α,β-unsaturated carbonyl framework in all the cases. Their trans geometry of the chalcone derivatives was further confirmed by single crystal X-ray diffraction (XRD) analyses. Further structural elaboration of the ambident electrophilic α,β unsaturated carbonyl (chalcone) moiety of the indole-chalcones and the analogous benzofuran chalcones with 2-aminothiophenol afforded novel benzothiezapine-appended indole and benzofuran hybrids, respectively. Sonogashira cross-coupling of 5-bromo-2-hydroxy-3 iodoacetophenone with terminal acetylenes followed by heteroannulation of the intermediate 3-alkynylated 5-bromo-2-hydroxyacetophenones afforded the corresponding 7-acetyl-2-aryl-5-bromobenzofurans in a single-pot operation. The oximes derived from the 7-acetyl–substituted 2-aryl-5-bromobenzofurans were subjected to Beckmann rearrangement with triflic acid in acetonitrile under reflux. We isolated the corresponding 7-amino-2-aryl-5 bromobenzofuran derivatives formed from hydrolysis in situ of the intermediate 7-acetamide 2-aryl-5-bromobenzofurans. Amino-dechlorination of the 4-chloroquinazoline derivatives with the 7-aminobenzofurans afforded novel benzofuran 4-aminoquinazoline hybrids. The prepared compounds were characterized using a combination of nuclear magnetic resonance (1H-NMR & 13C-NMR including 19F-NMR), infrared (IR) and mass spectroscopic techniques complemented with single crystal X-ray diffraction (XRD) analyses and/or density functional (DFT) method. The benzofuran-chalcone 203a–y derivatives were evaluated for anti-growth effect against the breast cancer (MCF-7) cell line by the MTT cell viability assay. Their mode of cancer cell death (apoptosis versus necrosis) was detected by Annexin V-Cy3 SYTOX staining and caspase-3 activation. The most cytotoxic compounds 203i and 203o were also evaluated for potential to inhibit tubulin polymerization and/or epidermal growth factor receptor-tyrosine kinase (EGFR-TK) phosphorylation. The experimental results were complemented with theoretical data from molecular docking into ATP binding site of the EGFR and colchicine binding site of tubulin, respectively. The benzofuran–4-aminoquinazoline hybrids 215a–j, on the other hand, were evaluated for antiproliferative propeties in vitro against the human lung cancer (A549), epithelial colorectal adenocarcinoma (Caco-2) and hepatocellular carcinoma (C3A) cell lines. The benzofuran-aminoquinazoline hybrids were also evaluated for potential to induce apoptosis and for their capability to inhibit EGFR-TK phosphorylation complemented with molecular docking (in silico) into the ATP binding site of EGFR. Mechanistic studies demonstrated that the benzofuran-appended aminoquinazoline hybrids 215d and 215j induced apoptosis via activation of caspase-3 pathway. Moreover, compounds 215d and 215j exhibited significant and moderate inhibitory effects against EGFR (IC50 = 29.3 nM and 61.5 nM, respectively) when compared to Gefitinib (IC50 = 33.1 nM). Molecular docking of compounds 215 into EGFR-TK active site suggested that they bind to the region of EGFR like Gefitinib does. / Chemistry / D. Phil. (Chemistry)

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