1. High-field 2D NMR spectroscopy of amanitin isomers
- Author
-
H. Vija, M. Haga, Endel Lippmaa, and Tõnis Pehk
- Subjects
NMR spectra database ,chemistry.chemical_classification ,Chemistry ,Stereochemistry ,Chemical shift ,Molecule ,General Materials Science ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Spectroscopy ,Two-dimensional nuclear magnetic resonance spectroscopy ,Cyclic peptide ,Amanitin - Abstract
The 1H, 13C and 15N NMR spectra of α−, β− and γ-amanitins and amaninamide were recorded at 11.7 T and analysed by various two-dimensional (2D) NMR spectroscopic techniques. All diastereotopic protons were assigned, and the side-chain conformations and the conformation of the hydroxyproline residue were determined. The observed 15N chemical shifts are caused by non-bonded interactions of the peptide nitrogens. 1H, 13C and 15N data are complementary to each other and show that the conformation of β-amanitin is slightly different from that of the other isomers, in accordance with the lower toxicity. The NOESY and carbonyl 13C1H chemical shift diagrams confirm the closeness of the conformations of amanitins in DMSO solution to that of β-amanitin in the crystalline state.
- Published
- 1989