Just a quick note to say that Daniel Lowe has released OPSIN v.2.9.0 , the first release since Oct 2023. This is now available via the EMBL-EBI OPSIN server . The release notes describe a mixture of minor bug fixes and improvements: Support for IUPAC recommended primed number-letter locants e.g. 2''a Command-line output now includes warnings e.g. ambiguity SMILES writer now starts from a * atom if one is present Added numbering to nicotine Correctly interpretation of locanted perhalo terms and perhaloalkylalkanes Improved additive bond formation for phosphoryl Corrected locants on tolyl and assume p-tolyl if unspecified triazine is now interpreted as 1,3,5-triazine if unspecified Corrected interpretation of dithiazolium Fixed rare SMILES writing bug where slashes could be inconsistent Fixed ylidenethenylidene being parsed as [ylidene][thenylidene] instead of [yliden][ethenylidene] Fixed bug in spiro superscript inferring when a bridge is length 0
I recently prepared a few slides on OPSIN for an internal presentation, and was looking for a simple use case. The first thing I tried turned out to be more interesting that I expected. If you visit the OPSIN website , there are three examples provided to illustrate its functionality. Daniel's original website, at the Uni of Cambridge, had 2,4,6-trinitrotoluene (TNT) as the example. With the move to EMBL-EBI and associated rewrite of the frontend, I thought about keeping this but decided that something more biologically-relevant would be appropriate. In the end, I comprised by keeping the 2,4,6- as a nod to the original, but used a saccharide instead: 2,4,6-tri-O-methyl-D-glucopyranose. Now click on "Search Google", to do a search using the InChIKey. My attention was drawn to the AI summary results, which I captured at the time (maybe you can tell when?) in the screenshot below: "The string UTLUVTKMAWSZKV-NEIVSKJXSA-N is an InChIKey (International Chemical Identifie...