UPLC-qToF-MSE Metabolomics to Investigate Century-Old Botanicals: A Case Study of Medicinal Aconite.

Despite their importance in botanical research, many herbaria worldwide have closed due to high maintenance costs and limited funding. These collections are especially valuable today, in the era of plant metabolomics, as they allow access to species that are typically inaccessible or otherwise difficult to recollect, enabling analysis through both untargeted and supervised methods. This study highlights this potential by analyzing historic samples of medicinal Aconitum from the New York Botanical Garden Rusby Collection. We hypothesized that applying modern LC-MS metabolomic techniques to historic plant collections would reveal chemical variation in medicinally important metabolites over time. Untargeted analysis facilitated chemotaxonomic identification of unidentified Aconitum samples in the collection. Three diester diterpenoid alkaloids, along with their derivatives, were identified and compared across specimens. Even after more than a century, several of these compounds were detectable, although detection varied among samples. Supervised analysis was used to identify additional chemical features useful as Aconitum marker compounds at the species level. By curating and prioritizing historic collections, future researchers can better understand the phytochemical profiles of key medicinal plants and how these profiles change over time.