Structure elucidation, complete NMR assignment and PM5 theoretical studies of new hydroxy-aminoalkyl-alpha,beta-unsaturated derivatives of the macrolide antibiotic josamycin
Copyright 2010 John Wiley & Sons, Ltd.
Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 48(2010), 4 vom: 26. Apr., Seite 286-96 |
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Weitere Verfasser: | , , , |
Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2010
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Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Anti-Bacterial Agents Josamycin HV13HFS217 |
Zusammenfassung: | Copyright 2010 John Wiley & Sons, Ltd. Four new hydroxy-aminoalkyl derivatives of alpha,beta-unsaturated macrolide-josamycin (2-5) have been synthesised and their structures have been studied by means of (1)H and (13)C NMR and FT-IR methods. Complete assignment of resonances in the (1)H and (13)C NMR spectra has been made on the basis of (1)H-(13)C HSQC, (1)H-(13)C HMBC, (1)H-(1)H COSY, (1)H-(1)H NOESY 2D experiments. Spectroscopic data indicated that for the derivatives 3 and 4 some equilibrium between two different structures exists in contrast to derivatives 2 and 5. The lowest-energy structures of the new derivatives of josamycin have been calculated and visualised by PM5 method at semi-empirical level of theory, taking into account the NMR and FT-IR data. The most significant differences between the structures of josamycin and its newly synthesised derivatives' were found in the conformation of the macrolide aglycone part and in the mutual orientation of the 4-O-isovalerylmycarosylmycaminose moiety relative to the aglycone part. PM5 semi-empirical calculations indicated that the structures of the new macrolide derivatives are stabilised by rather weak intramolecular hydrogen bonds in agreement with spectroscopic data. Antimicrobial properties of the new derivatives 2-5 as well as those having an acetate group at C-3 (6 and 7) were determined and compared to that of the parent macrolide antibiotic josamycin (1) |
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Beschreibung: | Date Completed 24.06.2010 Date Revised 21.11.2013 published: Print Citation Status MEDLINE |
ISSN: | 1097-458X |
DOI: | 10.1002/mrc.2574 |