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Application of the TORO technique of 1 H NMR to the structural analysis of cyclic peptide isomers having a slightly distorted symmetry from C 2
Author(s) -
Watanabe Eiji,
Tamaki Makoto,
Yamakura Fumiyuki,
Akiyama Minoru
Publication year - 2004
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1310
Subject(s) - chemistry , amide , crystallography , gramicidin s , stereochemistry , cyclic peptide , proton , nmr spectra database , nuclear magnetic resonance spectroscopy , proton nmr , spectral line , chemical shift , peptide , gramicidin , organic chemistry , physics , biochemistry , quantum mechanics , membrane , astronomy
The extended TORO technique was applied to the structural analysis of endo ‐ D ‐Tyr‐gramicidin S, cyclo(‐Val‐Orn‐Leu‐ D ‐Phe‐ D ‐Tyr‐Pro‐Val‐Orn‐Leu‐ D ‐Phe‐Pro‐), which has a slightly distorted symmetry from C 2 , by the insertion of D ‐Tyr and equivalent α‐proton chemical shifts in the 1 H NMR spectrum. All NMR signals of the two dominant isomers of this antibiotic with trans–trans prolines were determined by using the extended TORO technique with TOCSY and ROESY spectra. This technique is generally applicable for distinguishing overlapped signals of α‐ and amide protons from the main chains of peptides. Copyright © 2003 John Wiley & Sons, Ltd.