Copyright©2008 Antony Williams
I’ve reported previously on the fact that we are now adding publication details to chemical structures on ChemSpider. We have introduced the ability to do this in a manual fashion where anyone can associate a blog article, wiki article or scientific publication directly with one of more chemical structures but we are also looking to do this in an automated fashion. Project Prospect from the RSC seemed like an ideal opportunity for us to consider using their InChI association to harvest the titles and DOIs to make the association. This would be done after a discussion with the RSC to receive their blessing if possible, based on our previous interactions.
Today I investigated the possibilities of using the information available. I started with this article and clicked on the Enhanced HTMP View (Prospect View) and then used the Toolbox to Show the Compounds. The article is about the “Chemistry and biology of resorcylic acid lactones”. A partial screenshot of the type of molecules discussed in the article is shown below.
For_the_purpose of this blogpost notice the visually appealing forms of the structures and the stereochemistry on the molecules. Now, each of the marked compounds in the article is linked to details of the molecule. See below..each of the pink highlights is linked to the molecule and pops up a new box.
Looking at radicicol on Project Prospect and on ChemSpider we see a difference. In fact, compare with the structure shown above from the article. The difference is one of stereochemistry..there is no stereochemistry in the InChI or in the SMILES string. There are also issues with the structure depiction shown below and this has been discussed before relative to “Cleaning“.
As_previously discussed with Ginkgolide B there can be many versions of a structure on the ChemSpider database. We recently introduced the ability to search on a “skeleton” as shown below in the new Structure Search options.
When the skeleton for zearalonone is searched (same skeleton excluding H) I found 15 hits. Some are shown below. Notice the difference (highlighted with red boxes) structure to structure in terms of the presence/absence of the double bond inside the cycle, the difference between the OH and the =O and the specified stereochemistry. This search can be very useful for finding related structures and more examples will be given in the near future of using such searches.We DO find versions without specified stereochemistry but we are presently working on approaches to relate the stereo/non-stereo versions of structures to each others in a very visual manner. More will follow…Stumble it!