Genetic identification and subsequent LC-QTOF MS analysis of plant remains (Oenanthe spp.) could prove the cause of an undetermined sudden death

Abstract

In recent years, recorded cases related to forensic botany and, in particular, of plant poisoning have become rare. We report on the medicolegal characteristics of an undetermined sudden death (USD) of a woman in which scene there were remnants of a vegetal peeling. After the autopsy, macroscopic findings reported multiorgan failure and requested the investigation of the cause of death. Postmortem blood was firstly investigated on cyanide toxicity presumptively coming from a yucca-like root; however, found cyanide levels were under normality. Because of the lack of morphological features of the encountered plant remains, a genetic nrDNA ITS2 sequence investigation was followed. The resulting DNA sequence could identify the evidence as the water dropwort (Oenanthe spp.) which contains oenanthotoxin, a potent toxin that may be fatal, similar to the more commonly found in hemlock Conium or cowbane Cicuta species. A liquid chromatography-tandem high resolution mass spectrometry (LC-QTOF MS) was later applied to analyse the vegetal extract and stomach content and successfully confirmed the toxin existence. Medicolegal and analytical findings at the forensic laboratory were described, where both biological and chemical techniques could successfully conjugate, as an interdisciplinary research, and explain premortem symptoms and postmortem findings. Present data can be helpful in future investigation on poisoning cases by conjugated polyacetylenes. The present work tries to emphasize the often undervalued plant evidence in legal medicine diagnosis in the context of an unexplained death.