Chemistry is complex. Anybody who has been involved with the creation of electronic datafiles containing thousands of chemical compounds and associated data (chemical names, properties etc) will tell you that errors creep in. ChemSpider has >28 million unique chemical entities and these have been sourced from many different places/groups/individuals. Some of these have been deprecated as we have determined, both manually and algorithmically, that the data are in error. Over the years we have learned a lot about data quality and ways in which algorithms can be applied to data prior to deposition on ChemSpider.
Some obvious structure-based errors that can be checked for would include: hypervalency (e.g. pentavalent carbons), charge imbalance (a compound has no neutralizing counterion for example), absence of stereochemistry (e.g. a compound with 12 possible stereocenters only has one assigned). There are many other such errors that can be detected algorithmically. It’s the old adage of why apply a human to what a computer can fix. With this in mind we have been working on a system called the ChemSpider Validation and Standardization Platform (CVSP for short). This system will serve multiple purposes. It will be one of the foundation blocks for checking structure-based data for our publications (i.e. catch bad chemistry before it is published!), it will be used for validating chemistry for our databases (Natural Product Updates, Methods in Organic Synthesis and Catalysts and Catalyzed Reactions), it will be used to check and validate depositions going into ChemSpider, it will serve data related to the Open PHACTS project and it will serve the community by providing an online website where you can upload your own SDF files (and other file formats in future) to validate the structures.
I won’t go into detail here about all of the functionality and capability of the system as we will discuss this in further detail on this blog. However, we will be unveiling the system in its present form at the ACS meeting in Philadelphia. Come along and meet some of the team involved in building CVSP and give us your feedback!