InChI isotopologue and isotopomer specifications

Area of Science:

• Chemical informatics
• Analytical chemistry
• Data science

Background:

• The International Union of Pure and Applied Chemistry (IUPAC) International Chemical Identifier (InChI) is a standard for chemical structure representation.
• Current InChI limitations exist in fully representing isotopically-resolved chemical entities, especially with ambiguous isotope localization.
• Accurate chemical identification is crucial for analytical instrumentation like NMR and mass spectrometry.

Purpose of the Study:

• To propose an extension to the InChI standard for improved representation of isotopically-resolved chemical entities.
• To enhance the interpretation of the existing isotopic layer and introduce a new isotopologue layer.
• To support unique identification of chemical features detected in analytical measurements.

Main Methods:

• Development of an extended InChI standard specification.
• Incorporation of an improved isotopic layer interpretation.
• Introduction of a novel isotopologue layer for ambiguous isotope localization.

Main Results:

• A proposed extension to the InChI standard capable of representing isotopically-resolved chemical entities with varying ambiguity.
• Enhanced capability for unique identification of chemical features from analytical data.
• Improved support for annotating analytical datasets.

Conclusions:

• The proposed InChI extension facilitates better characterization of chemical entities in analytical data.
• This advancement supports the FAIR data principles (Findable, Accessible, Interoperable, Reusable) for chemical datasets.
• The extension promotes Open Science practices within the chemistry community.