Tissue-specific profiling of ergot alkaloids and related compounds in Thai’s Ipomoea asarifolia (desr.) Roem. & Schult. using LC-HRMS

Ipomoea asarifolia (Desr.) Roem. & Schult. is known for livestock toxicity, primarily associated with ergot alkaloids and indole diterpenes produced by its symbiotic fungus, Periglandula. In this study, we investigated the plant’s phytochemical diversity across various organs using liquid chromatography–high-resolution mass spectrometry (LC-HRMS). Metabolite profiling putatively identified diverse ergot alkaloids (e.g. lysergic acid amide, lysergic acid α-hydroxyethylamide and ergobalansine) and indole diterpenes (e.g. 6,7-dehydroterpendole A and paspaline) distributed throughout the plant. However, semi-quantitative analysis revealed their accumulation is highly tissue-specific, peaking in young leaves and mature seeds while remaining notably low in roots and stems. Furthermore, we detected a rich background of plant-derived bioactive metabolites, including phenolic acids (e.g. dicaffeoylquinic acids isomers), flavonoids, coumarins, terpenoids, and steroidal sapogenins. This study provides the first comprehensive tissue-specific metabolite profile of I. asarifolia, expands its known chemical profile by putatively identifying additional Periglandula-derived ergot alkaloids and indole diterpenes, and reveals their organ-specific accumulation.