Targeted and Untargeted Mass Spectrometry Do Not Detect Grayanane-Type Toxins in Monotropa uniflora L

Monotropa uniflora L. ("ghost pipe"), is a North American traditional medicinal plant which has recently seen an increase in consumption nationwide. However, a single 1889 study reported the presence of grayanotoxin I in M. uniflora, generating controversy regarding its safety. It is essential to revisit this claim of toxicity given Monotropa uniflora's resurgence in popularity. We applied more sensitive analytical techniques to determine the possible presence of grayanotoxins in a diverse sampling of M. uniflora, using mass spectrometry and MS²-based molecular networking. Across 50 M. uniflora samples, neither grayanotoxins nor structural analogues were detected, refuting the earlier analysis.