Mixed toxin profiles in two new and one known species of Inocybe (Inocybaceae) from northern China

Mushroom poisoning has become a serious food safety issue in China. Poisoning incidents caused by species of Inocybaceae have been continuously reported from tropical to temperate regions of China in recent years. Many species of Inocybaceae contain muscarine, which stimulates the parasympathetic nervous system; some also contain psilocybin, resulting in hallucinations, and a few even contain amatoxins.

In this study, two new species of the I. aeruginascens group, Inocybe tumericolor and I. subaeruginascens, are described based on combined morphological evidence and multilocus phylogenetic analyses (ITS, LSU, and rpb 2). Subsequently, a targeted multi-toxin analysis using liquid chromatography-tandem mass spectrometry (LC-MS / MS) was performed on these two new species together with the north-temperate species I. asterospora, quantifying 12 toxins, including muscarine, two isoxazole derivatives, three tryptamine alkaloids, three amatoxins, and three phallotoxins.

Mixed profiles of muscarine, psilocybin, and psilocin were uncovered, whereas the other nine toxins were below the detection limits in all tested samples. Inocybe tumericolor contained psilocybin (1692.2–2758.7 mg / kg) and psilocin (77.8–134.8 mg / kg) but no muscarine; I. asterospora contained muscarine (79.6–1182.6 mg / kg) and psilocybin (107.1–765.2 mg / kg) but no psilocin; whereas I. subaeruginascens contained all three: muscarine (480.8–752.6 mg / kg), psilocybin (1023.0– 2731.2 mg / kg), and psilocin (71.7–148.4 mg / kg).

Detailed morphological characters and phylogenetic analyses of the two new species are also provided. These results may enrich knowledge of the diversity of Inocybe species and their toxins and provide scientific evidence for elucidating toxin evolution and facilitating the early diagnosis and treatment of mushroom poisoning. The presence or absence of preformed psilocin may affect the onset of hallucinogenic symptoms, underscoring the need for species-level identification in poisoning management.