Oral Presentation Australian & New Zealand Society of Magnetic Resonance Conference 2017

Application of Density Function Theory (DFT) for the calculation of 1H and 13C NMR chemical shifts for structure elucidation of complex natural products. (#35)

Gregory Pierens 1 , L.C. Forster 2 , A.M. White 2 , K.L. Cheney 3 , M.J. Garson 2
  1. The University of Queensland, Brisbane, QLD, Australia
  2. School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane
  3. School of Biological Sciences, The University of Queensland, Brisbane

NMR spectroscopy is a powerful tool for determining the structure of isolated natural products. The use of 1H and 13C NMR chemical shifts is the most important parameter in this process since it reflects the local chemical environment of the individual protons and carbons within the compound.

The dramatic increase in power of modern computer workstations, coupled with advances in software, has made it possible to calculate the chemical shifts for a given  compound and use them to help guide the elucidation of the structure or support the proposed structure of the natural product.

An overview of the application of density functional theory to the calculation of 1H and 13C chemical shifts and structure verification of marine terpenes will be discussed.

These examples will include:

  • Epoxygoniolide-1 (1),1 a cytotoxic spiroepoxide lactone isolated from the conspicuously patterned nudibranch, Goniobranchus splendidus, possessing spiroepoxide, lactone, enal, and masked dialdehyde functionalities.
  • Pustulosaisonitrile-1 (2),2 an antimalarial isocyanoterpene characterized from Australian nudibranch Phyllidiella pustulosa, possessing significant challenges for absolute structural elucidation owing to the difficult C-6/C-7 stereochemical relationship, and the remote oxabicyclo[2.2.1] ring system.

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  1. 1. Forster L.C. et al. (2017) ACS OMEGA. 2:2672-77 2. White A.M. et al. (2017) J Org Chem submitted