Structural Diversity of Steroidal Glycoalkaloids in Potato (Solanum tuberosum) Leaves Revealed by Untargeted UHPLC–QTOF Metabolomics
- Rousseau, G. , Krings, B. & Muhovski, Y. (2026). Structural Diversity of Steroidal Glycoalkaloids in Potato (Solanum tuberosum) Leaves Revealed by Untargeted UHPLC–QTOF Metabolomics. Potato Research, accepted:
| Type | Journal Article |
| Year | 2026 |
| Title | Structural Diversity of Steroidal Glycoalkaloids in Potato (Solanum tuberosum) Leaves Revealed by Untargeted UHPLC–QTOF Metabolomics |
| Journal | Potato Research |
| Label | Muhovski-U1 |
| Volume | accepted |
| Endnote keywords | Cultivar variation · Glycosylation diversity, Solanum tuberosum, Specialized metabolism, Steroidal glycoalkaloids, UHPLC-QTOF, Untargeted metabolomics |
| Abstract | Steroidal glycoalkaloids (SGAs) are nitrogenous defence metabolites characteristic of Solanum species. Although the major potato SGAs α-solanine and α-chaconine are well known, the full structural scope of glycoalkaloids in vegetative tissues remains largely uncharacterized. Here, we applied untargeted ultra-highperformance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) to profile SGA diversity in the leaves of three cultivars (Lady Rosetta, Charlotte, and Bintje). High-resolution MS/MS data enabled annotation of over 30 tri-glycosylated alkaloids differing in both the steroidal backbone and glycosylation topology. Three compounds, α-solanine, α-chaconine, and α-solamargine, were verified with authentic standards (Metabolomics Standards Initiative (MSI) level 1). Besides classical solanidine-based SGAs, multiple metabolites were consistent with solasodine- and solaverol-type aglycones (MSI level 2–3), revealing unrecognized biosynthetic branches. SGA composition varied strongly among cultivars: Lady Rosetta exhibited the broadest chemical repertoire and the highest abundance of oxygenated SGAs, whereas Bintje displayed a restricted solanidine- dominant profile. Several low-abundance SGAs bearing partially unsaturated or over-oxidized aglycones (m/z 396, 412 and 428) were reproducibly detected and likely represent genuine metabolites, hinting at additional, low-flux biosynthetic routes. This comprehensive profile extends the structural landscape of potato SGAs and underscores the capacity of untargeted UHPLC–QTOF metabolomics to resolve complex steroidal metabolite networks. The observed cultivar-specific signatures suggest differential regulation of late-stage oxidation and glycosylation steps, potentially contributing to varietal variation in chemical defence. |
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| Authors | Rousseau, G., Krings, B., Muhovski, Y. |
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