Availability of data and materials
All supplemental materials are available at: https://doi.org/10.6084/m9.figshare.7150964. This includes the original proposal, all feedback and responses on the proposal as well as the presentation of the proposal given at Metabolomics 2018, the annual conference of the International Metabolomics Society in Seattle, Washington USA.
Competing interests
The authors have no competing interests.
Funding
This work has been supported by the National Science Foundation [NSF 2020026 to HNBM]. NSF had no role nor influence on this work.
PRS and RS were supported by the PhenoMeNal project, funded by European Commission's Horizon2020 programme, grant agreement number 654241.
MS was supported by NBDC Togo Project, funded by MEXT, Japan.
ELS acknowledges funding support from the Luxembourg National Research Fund (FNR) for project A18/BM/12341006.
Authors' contributions
HNBM chaired the InChI Isotopologue Working Group, created the initial draft of the extension, and wrote the initial draft of this manuscript. All other authors provided multiple rounds of revisions to both the extension and the manuscript.
Acknowledgements
We acknowledge the feedback on the extension provided both by the IUPAC Division VIII InChI Subcommittee and by the metabolomics scientific community. We also posthumously acknowledge Igor Pletnev’s invaluable work developing and maintaining the InChI libraries and software for over 15 years.
Authors' information
HNBM – Professor in the Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY USA; Bioinformatics and Data Analysis Section Editor-in-Chief of Metabolites; Associate Director, Institute for Biomedical Informatics, University of Kentucky, Lexington, KY USA.
PRS – Associate Member of Faculty, senior researcher at the Oxford e-Research Centre, Department of Engineering Science, University of Oxford, Oxford, UK.
RMS- Vice President, Head of Application Development. Bruker BioSpin GmbH, Germany.
MA – Professor and Head of DNA Data Bank of Japan, National Institute of Genetics, Japan; Team Leader of Metabolome Informatics, RIKEN Center for Sustainable Resource Science.
ELS – Full Professor and Head of the Environmental Cheminformatics (ECI) group at the Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg; Special Advisor to the Rectorate for Open Science and Research Data Management.