Related Experiment Video
Updated: Jul 12, 2026

Pure Shift Nuclear Magnetic Resonance: a New Tool for Plant Metabolomics
Published on: July 31, 2021
Complete (1)H NMR spectral fingerprint of huperzine A
Matthias Niemitz1, Reino Laatikainen, Shao-Nong Chen
1Department of Biosciences, University of Kuopio, FIN-70211 Kuopio, Finland.
Abstract:
Complete analysis of the (1)H NMR spectrum of huperzine A, 1-amino-13-ethylidene-11-methyl-6-aza-tricyclo[7.3.1.0(2, 7)]trideca-2(7),3,10-trien-5-one, a Lycopodium alkaloid and anti-Alzheimer drug lead containing an ABCD(E)(MN)(OP)X(3)Y(3)-type system of 15 nonexchangeable proton spins, is reported for the first time, and earlier assignments are corrected. The complete (1)H parameter set of 11 chemical shifts clarifies the diastereotopism of both methylene groups, and provides a total of 38 observed H,H-couplings including 31 long-range ((4-6)J) connectivities. The NMR data is consistent with the comparatively rigid alicyclic backbone predicted by molecular mechanics calculations, and forms the basis for (1)H NMR fingerprint analysis for the purpose of dereplication, purity analysis, and elucidation of structural analogs.
Related Concept Videos
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
NMR Spectroscopy Of Amines
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
NMR Spectroscopy of Aromatic Compounds
¹H NMR Signal Integration: Overview
Proton (¹H) NMR: Chemical Shift
Absorption signals of all the protium nuclei in a...
