Determination of cyclopeptide toxins in Amanita subpallidorosea and Amanita virosa by high-performance liquid chromatography coupled with high-resolution mass spectrometry

• Thirteen cyclopeptides and two unknown compounds are identified or observed from A. subpallidorosea and A. virosa by HPLC coupled with HR-MS.
• Virotoxins that previously appeared to be restricted to A. virosa are identified in A. subpallidorosea.
• The total amount of toxins in the tested A. subpallidorosea is significantly higher than that in the tested A. virosa.
• The existence of cyclopeptide toxins is consistent with the molecular phylogenetic relationships.

Amanita subpallidorosea is a recently discovered lethal Amanita sect. Phalloideae species found in China that is clustered with A. virosa in the same clade based on molecular phylogenetic analysis. However, the cyclopeptide toxin contents of these lethal mushrooms remain poorly studied. In this study, the cyclopeptide toxins in A. subpallidorosea were reported for the first time and the cyclopeptide compositions of A. subpallidorosea and A. virosa species were systematically analyzed. Thirteen cyclopeptides and two unknown compounds were identified or observed from these two lethal mushrooms by high-performance liquid chromatography coupled with high-resolution mass spectrometry. Of the known cyclopeptides, the virotoxins alaviroidin, viroisin, and viroidin, which were previously thought to be restricted to A. virosa, were identified in A. subpallidorosea. The cyclopeptide compositions showed that there are diversities in the kinds and levels of amatoxins, phallotoxins, and virotoxins between A. subpallidorosea and A. virosa species, and that the amount of total toxins in the tested A. subpallidorosea is significantly higher than that in the tested A. virosa. Furthermore, consistency of the cyclopeptide toxins with the molecular phylogenetic relationships was demonstrated.