OPSIN chemical name-to-structure tool moves to EMBL-EBI

The Open Parser for Systematic IUPAC Nomenclature (OPSIN) – a free open-source tool that turns chemical names into digital molecular structures – has moved to EMBL-EBI.

Originally developed and hosted by the University of Cambridge, OPSIN has become a critical tool for translating chemical names into structured chemical representations. With over 14000 unique visitors per month to the website, it has become widely used by researchers around the world.

OPSIN provides a much-needed function to the chemical and life sciences community by converting complex IUPAC names – a standard format used by chemists to describe molecular structure – into a depiction of the molecule as well as machine-readable formats such as Simplified Molecular Input Line Entry System (SMILES) and InChI.

From name to structure 

In simple terms, OPSIN takes a chemical name – for example 1,3,7-trimethylpurine-2,6-dione, the IUPAC name for caffeine – and decodes it into a format that computers can understand and process. 

This is a crucial step for cheminformatics, where molecules need to be interpreted not just by humans but also by computers. While a chemical name is readable to a trained chemist, a machine-readable representation of the structure allows that same compound to be searched, visualised, and processed in digital systems.

OPSIN supports the scientific community by:

• helping scientists maintain accurate and consistent naming and structure information
• integrating with text-mining tools to extract chemical entities from millions of scientific publications and patents
• supporting automated workflows by providing the open-source OPSIN code that can be integrated into scripts and larger workflows

A new home at EMBL-EBI 

The migration of OPSIN to EMBL-EBI ensures the long-term sustainability of the tool and supports better integration of OPSIN with EMBL-EBI’s other chemical biology services.

OPSIN will now also benefit from inclusion in EBI search – EMBL-EBI’s central search engine – making it easier to find. Integration of OPSIN with UniChem also supports cross-linking of OPSIN’s output to many other chemical biology databases, including PubChem, ChEBI, and DrugBank.

Find the new EMBL-EBI hosted OPSIN web portal and get access to the OPSIN open-source code on GitHub.