Conformational analysis of phorboxazole bis-oxazole oxane fragment analogs by NMR spectroscopy and molecular modeling simulations
Copyright (c) 2007 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 46(2008), 1 vom: 01. Jan., Seite 36-41 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Heterocyclic Compounds, 4 or More Rings Oxazoles phorboxazole A 165883-76-1 |
| Zusammenfassung: | Copyright (c) 2007 John Wiley & Sons, Ltd. We present a detailed conformational study of a simplified synthetic analog of the bis-oxazole oxane fragment found in the cytostatic agents phorboxazole A and B based on results from NMR spectroscopy and molecular modeling simulations. Complete 1H and 13C resonance assignments for the bis-oxazole oxane system were carried out through the use of COSY, HSQC, HMBC, TOCSY, and HSQC-TOCSY experiments, and its conformational preferences in solution were investigated by analysis of 3J(HH) coupling constants and NOE enhancements obtained from 1D and 2D NOESY experiments. In order to solve inconsistencies from our preliminary structural studies, simulated annealing studies were performed to thoroughly sample the phase space available to the molecule. Our results reveal that the six-membered oxane ring, which constitutes the most important moiety regarding the three-dimensional (3D) structure and flexibility of the analog, exists in rapid equilibrium between its two accessible chair conformers in an approximate ratio of 70:30. The information gathered from these studies will be of critical importance in our efforts to prepare novel compounds with phorboxazole-like structure and activity |
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| Beschreibung: | Date Completed 25.04.2008 Date Revised 24.11.2016 published: Print Citation Status MEDLINE |
| ISSN: | 1097-458X |