Extended Data Fig. 10. The 315 molecular structures not contained in HMDB annotated with high confidence in the human dataset.

Confidence score threshold 0.64 was used. For none of these structures, reference MS/MS data are available. Structures are shown with identification number (ID), molecular formula and COSMIC confidence score. Structures present in the latest version of HMDB (Feb 2021) are marked by an asterisk. Colors indicate compound classes. Notably, 48 compounds were annotated as proteinogenic peptides; these structures were absent from HMDB but are clearly no novel metabolite structures. Lipid structures must be interpreted with some care: It is understood that neither COSMIC nor any other method can deduce, say, the position of the double bond in a carbon chain from MS/MS data alone; rather, this happens to be the candidate present in our biomolecule structure database.