An interesting case study of a correct structure assignment for aquatolide appeared in JOC. It’s interesting from several points of view. First, it nicely shows how one can effectively use reach information from free induction decay (FID), which is lost (or masked) in Fourier-transformed spectra. Second, it emphasizes importance of data sharing and demonstrates crucial role of ‘research parasites‘ in scientific ecosystem. Third, the paper has seven-point manifest in the conclusions section.
The introduction sets the stage for the rest of the paper with quite a bold quote:
The present study demonstrates that practically everything the chemist needs to know for a correct structural elucidation process is contained in the proton NMR FIDs.
In general, it looks like the actual structure of aquatolide was just a decoration for authors to write their “1D HNMR manifesto”. Seriously people, no cheating with 2D, play around with apodization and do the full autopsy on your 1Ds first! I wonder what would they say about 2DJ NMR.
Confirmation employing 2D data sets is appropriate after the 1D spectrum has been thoroughly examined and can focus on issues that are otherwise not fully resolved.
From the practical side, the authors suggest a nice and clear graphic method of assigning coupling constants, Quantum interaction and linkage tables (QuILTs). It is applicable to 1D as well as 2D spectra and could be indeed a good standard for reporting NMR spectra instead of (or together with) text transcripts and actual pictures of spectra used nowadays.
I did my PhD in medicinal chemistry/chemical biology of G protein-coupled receptors and then explored some chemical biology of non-coding RNA as a postdoc. Currently I'm working in a small biotech company in San-Francisco Bay area as a research chemist. I'm writing about science, which catches my attention in rss feed reader and some random thoughts or tutorials.
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