Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 26 for “"HMBC"”.
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Analysis of polymeric extractives of Western Juniper (Juniperus occidentalis) heartwood
… Fourier Transformed Infrared spectroscopy and 2D HMBC NMR (two dimensional Heteronuclear Multiple Bond Correlation) show that this is a heterogeneous polymeric material which reveals three long-range correlations. A long range labelled carbonyl correlation at around δ = 6.00 ppm corresponding to …
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Naturstoffe aus Färbe- und Heilpflanzen
… TOCSY, den heteronuklearen Experimenten HMQC und HMBC sowie den kombinierten NMR-Experimenten HMQC-COSY und HMQC-TOCSY vorgenommen. Die Anordnung der axial- und äquatorialständigen Protonen der Aglyca wurde mittels ROESY- oder NOESY-Messungen ermittelt. Auch die interglycosidischen Verknüpfungen …
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Antiproliferative Natural Products from the Madagascar Rainforest
… 2D NMR experiments, including COSY, HSQC/HMQC, HMBC, and ROESY/NOESY sequences, mass spectrometry, and chemical conversion. In addition, ten known compounds were obtained from five of the extracts. Studies on the remaining extracts were suspended due to various reasons. A multi-step synthesis of …
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Προσδιορισμός δομής, διαμορφωτικές ιδιότητες και ανακάλυψη πιθανών στόχων του παραγώγου του κινναμωμικού οξέος NGI25
… (COSY, NOESY) και ετεροπυρηνικά (HSQC, HMBC) πειράματα για τον προσδιορισμό των πρωτονίων και των ατόμων άνθρακα. Μετά την ταυτοποίηση της δομής, το NGI25 υποβλήθηκε σε υπολογιστικές μελέτες για να αποκαλυφθούν οι πιο ευνοϊκές διαμορφώσεις του. Συγκεκριμένα, πραγματοποιήθηκαν μελέτες MD …
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Isolation and Structure Elucidation of Antiproliferative and Antiplasmodial Natural Products from Plants
… were elucidated by using 1D (1H and 13C), 2D (HMBC, HSQC, COSY, NOESY) NMR spectroscopy and mass spectrometry. The structures of the compounds were also confirmed by comparing them with reported values from the literature. Compounds 2.1 and 2.2 showed moderate antiproliferative activity against …
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Isolation and Structural Elucidation of Compounds from Natural Products
… in one case, x-ray crystallography. The HSQC and HMBC data along with comparison of these data with reported literature values confirmed the structures. The aforementioned isoflavones and pterocarpans showed varying cytotoxicity to ovarian cancer cell lines, with the isoflavone vogelin E being the …
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The application of nuclear magnetic resonance in the structural elucidation of natural products
… and Heteronuclear Multiple Bond Coherence (HMBC) experiments were essential for complete assignment of the quaternary groups. The stereochemical designation of some of the compounds was confirmed using the Rotating Frame Overhauser Enhancement Spectroscopy (ROESY) experiment which proved to …
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Synthetic studies and biological evaluation of chromone - 3 - carbaldehydes
… NMR (1H, 13C and DEPT), 2D NMR (COSY, HSQC and HMBC), IR and elemental analysis (CHN analysis). Selected synthesized chromone derivatives were evaluated in vitro for two biological assays; namely trypanocidal activity and cytotoxicity. Among all tested compounds, 41A, 55B and 63D displayed …
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Insektizide Rocaglamid-Derivate und Verwandte Verbindungen aus Aglaia-Arten (Meliaceae)
… (darunter 2D-Experimente wie H-H-COSY, HMQC, HMBC und ROESY) sowie durch Massenspektrometrie. Die Untersuchungen zur Struktur-Wirkungs-Beziehung ergaben für die Rocaglamide V, Z und AA eine starke insektizide Aktivität gegenüber Raupen von S. littoralis mit LC50- und EC50-Werten von 2.0 bis …
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Self-Assembly of Calix[4]Arene Amine Derivatives
… of nOe, serial dilution, high temperature and HMBC NMR spectroscopic techniques were employed. The results of these revealed that self-assembly was occurring in solution and it is believed that two kinds of self-assembled structures are present, namely the heterodimerisation form and the …
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Isolation and Structure Elucidation of Anticancer and Antimalarial Natural Products
… 2D NMR spectroscopy including COSY, HASQC, HMQC, HMBC, and NOESY sequences, mass spectrometry, UV, IR, ECD, optical rotation, and chemical conversions. In addition, ten known compounds were isolated from another five of the extracts, while studies on the remaining extracts were suspended due to …
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Nitrosoarenes: magnetic anisotropy, donor-acceptor bonding and host-guest chemistry
… including: 1H, 13C, NOE, COSY, HSQC, and HMBC NMR spectroscopy. Also studied is the electron donor-acceptor (DA) bonding ability of the N=O group of N,N-dimethyl-4-nitrosobenzene (DMANB) and N,N-diethyl-4-nitrosobenzene (DEANB), in the monomeric state, as they complex and co-crystallize …
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Karakterisering van Grubbs-tipe prekatalisatore met behulp van kernmagnetiese resonansspektroskopie
… do the following experiments: 1H, COSY, HSQC and HMBC, which took four hours. The next step was the DEPT135 experiment of three hours, and finally the 13C experiment of seven hours. The maximum amount of information could be obtained in this way. The combined NMR parameters for this study was …
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Σύνθεση αναλόγων των κανναβινοειδών CBD, CBN, CBG, CBC και έλεγχος της δράσης τους στο κανάλι TRPΑ1
… τύπων άνθρακα. Επιπλέον, εφαρμόστηκε η τεχνική HMBC (Heteronuclear Multiple Bond Correlation), η οποία παρείχε πληροφορίες για μακρινές συσχετίσεις μεταξύ πρωτονίων και ανθράκων. Η ολοκληρωμένη αυτή προσέγγιση συνέβαλε καθοριστικά στη διασαφήνιση της δομής των τελικών προϊόντων. Η βιολογική …
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3-(R)-Hydroxysäuren als Produkte selektiven Fettsäureabbaus
… (1H-NMR, 13C-NMR, 13C-DEPT, H/H-COSY, HMQC, HMBC). Linolsäure wurde von Stenotrophomonas maltophilia zu 3-Hydroxy-Z6-dodecensäure, 3-Hydroxy-Z5,Z8-tetradecadiensäure und 3-Hydroxy-Z7,Z10-hexadecadiensäure umgesetzt. In einem anschließenden Substratscreening wurden 32 Verbindungen als Edukte …
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Spectroscopic and synthetic studies relating to a dirhodium hydroformylation catalyst
… <sup>1</sup>H and <sup>31</sup>P, and 2D COSY, HMBC, and HMQC were employed and indicated the formation of the key catalyst, [rac-Rh<sub>2</sub>H<sub>2</sub>(μ-CO)<sub>2</sub>(CO)<sub>4</sub>(et,ph-P4)]<sup>2+</sup>, 4, and a number of other Rh-phosphine species on and off the catalytic cycle. …
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Phytochemical and pharmacological studies on some endemic Yucatecan medicinal plants
… using 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and NOESY and ROESY) NMR and mass spectrometry analysis as sakurasosaponin. The molluscicidal and antifungal activities of sakurasosaponin have been reported but no studies on its cytotoxic activity have been previously reported. The …
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Naturstoffe aus Heilpflanzen und marinen Organismen
… und den heteronuklearen Experimenten HMQC und HMBC ermittelt. Die relative Konfiguration wurde durch die Auswertung von ROESY-Spektren festgelegt. Die Analyse der Steroidgemische erfolgte nach Trimethylsilylierung mittels GC-MS-Messungen. Aus den Heilpflanzen Zizyphus spina-christi und …
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Antimalarial activity of hypoxis colchicifolia, bak, mimusops caffra, E. Mey. ex A.DC and mimusops obtusifolia, lam from South Africa
… of 2D-NMR (1H-1H, 13C, DEPT, COSY, HMQC, HMBC and NOESY) and infrared (IR). The preliminary phytochemical analysis of plants’ extracts revealed the presence mainly of saponins, tannins, alkaloids and flavonoids. Methanol extracts of the plants exhibited strong scavenging of …
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Characterizing peptide-modifying enzyme activity in RiPP biosynthesis
… assignments. Using alkylation-assisted HMBC correlations, it was demonstrated that these products also contain 5TO resulting in a revision of these previously reported structures. The role of 5TO-containing peptides in copper detoxification was investigated and this emerging class of …
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