May 1, 2008
by Ryan Sasaki, NMR Product Manager, ACD/Labs
I’ve blogged several times about the progress and applications of automated structure verification with the help of ACD/Labs software.
There are really two main approaches right now:
- Combined verification which includes automatically verifying the correspondence between a proposed chemical structure and the 1D 1H and 2D HSQC spectra. I’ve blogged about the publications and applications of this method previously.
- 1H only verification. Of course the first approach is preferable from an accuracy standpoint as the additional information gained from the HSQC spectrum increases the selectivity and specificity of the results.
However, I always get questions on how well we perform on 1H NMR only because in some organizations and environments it is simply not feasible to always run an HSQC in tandem with a routine 1H NMR analysis.
As mentioned in previous posts, we’ve already conducted a validation study on this approach and it was published in a 2006 article in MRC. We’ve continued to investigate and validate this approach and we recently presented our latest results using 1D 1H NMR data only at ENC 2008.
The poster highlighted a study on the automatic evaluation of over 15,000 Aldrich compounds and spectra from Aldrich NMR Spectra Database.
The results of this study revealed that the software was able to confirm 88%of all spectra as consistent and flagged less than 5% as inconsistent.
One of the more interesting discoveries in this study was that it revealed some truly wrong structures in the Aldrich NMR database.
More information on these as well as shortcomings in prediction, processing, and analysis are provided in the poster that can be downloaded:
http://www.acdlabs.com/download/publ/2008/enc08_aldrich.pdf