What is the form of muscimol from fly agaric mushroom (Amanita muscaria) in water? An insight from NMR experiment supported by molecular modeling.
Teobald Kupka, Małgorzata A Broda, Piotr Wieczorek
Magnetic resonance in chemistry : MRC June 2020 DOI: 10.1002/mrc.4990 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Theoretical or experimental spectroscopic study Peer reviewed |
|---|---|
| Keywords | Giao nmr Nmr in water Molecular modeling Muscimol |
| Key findings | The authors report that NMR spectra of muscimol in water, supported by density functional theory calculations, favor the zwitterion form, in contrast to the NH isomer previously determined in DMSO solution. They also report several previously unavailable proton and carbon J-couplings and note that the C3 and C5 signal positions are reversed in both solvents. |
Abstract
The biologically active alkaloid muscimol is present in fly agaric mushroom (Amanita muscaria), and its structure and action is related to human neurotransmitter γ -aminobutyric acid (GABA). The current study reports on determination of muscimol form present in water solution using multinuclear 1 H and 13 C nuclear magnetic resonance (NMR) experiments supported by density functional theory molecular modeling. The structures of three forms of free muscimol molecule both in the gas phase and in the presence of water solvent, modeled by polarized continuous model, and nuclear magnetic isotropic shieldings, the corresponding chemical shifts, and indirect spin-spin coupling constants were calculated. Several J-couplings observed in proton and carbon NMR spectra, not available before, are reported. The obtained experimental spectra, supported by theoretical calculations, favor the zwitterion form of muscimol in water. This structure differs from NH isomer, previously determined in dimethyl sulfoxide (DMSO) solution. In addition, positions of signals C3 and C5 are reversed in both solvents.
Citations in the library
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