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Structure elucidation, complete NMR assignment and PM5 theoretical studies of new hydroxy-aminoalkyl-alpha,beta-unsaturated derivatives of the macrolide antibiotic josamycin.
- Source :
-
Magnetic resonance in chemistry : MRC [Magn Reson Chem] 2010 Apr; Vol. 48 (4), pp. 286-96. - Publication Year :
- 2010
-
Abstract
- 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).<br /> (Copyright 2010 John Wiley & Sons, Ltd.)
- Subjects :
- Anti-Bacterial Agents classification
Anti-Bacterial Agents pharmacology
Bacteria drug effects
Josamycin classification
Magnetic Resonance Spectroscopy
Models, Molecular
Molecular Structure
Spectroscopy, Fourier Transform Infrared
Anti-Bacterial Agents chemistry
Josamycin chemistry
Quantum Theory
Subjects
Details
- Language :
- English
- ISSN :
- 1097-458X
- Volume :
- 48
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Magnetic resonance in chemistry : MRC
- Publication Type :
- Academic Journal
- Accession number :
- 20186698
- Full Text :
- https://doi.org/10.1002/mrc.2574