NMR Identification and MS Conformation of the Scopolamine Neurotoxin

摘要

An unidentified white powder collected as evidence in an intelligence investigation was characterized exclusively by NMR analysis. A small fraction of the powder dissolved in D2O was subjected to quantitative 1H and 13C(1H) experiments and a series of two-dimensional correlation techniques, including 1H-1H COSY and NOESY as well as 1H-(exp 13)C HSQC and HMBC spectroscopy. These were used to elucidate the molecular structure of the powder's major component and positively identify it as the scopolamine biotoxin. To confirm the NMR results, an ethanol/H2O solution of the powder was analyzed by direct infusion into an ion trap mass spectrometer. A prominent base signal at m/z 304.1 was observed, consistent with the protonated molecular ion of scopolamine. Comparisons of 1H and '3C chemical shift values and JHH values measured from the NMR data were found to agree very favorably with previously reported values for scopolamine in D2O.