Determination of cyclopeptide toxins in Lepiotaceous fungi by Ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry
Lepiotaceous fungi are a group of mushrooms in the family Agaricaceae. Several Lepiota species were reported poisonous and contained cyclopeptide toxins which could cause acute liver failure. However, the cyclopeptide toxin contents of these lethal mushrooms and species from related genera remain poorly studied. In this study, a simple, rapid and sensitive method,ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry(UPLC-ESI-MS/MS), for the simultaneous determination of α-amanitin, β-amanitin, γ-amanitin, phalloidin(PHD) and phallacidin(PCD) was used to detect the peptide toxins from 114 specimens. No cyclopeptide toxins were detected from the following genera: Agaricus(A. abruptibulbus, A.guizhouensis, A. luteofibrillosus, A. purpurellus, A. sinoplacomyces and A. xanthodermus), Chlorophyllum(C. globosum, C.hortense, C. lusitanicum and C. molybdites), Coniolepiota(C. spongodes), Heinemannomyces(H. splendidissima), Hymenagaricus(H. ardosiicolor and H. epipastus), Leucoagaricus(La. rubrotinctus), Leucocoprinus(Lc. birnbaumii and Lc. lilacinogranulosus),Macrolepiota(M. detersa, M. subcitrophylla and Macrolepiota sp.), Melanophyllum(M. cf eyrei) and Micropsalliota(M. furfuracea,M. globocystis and Micropsalliota sp.). In the genus Lepiota, cyclopeptide toxins were also not detected from L. aspera, L. attenuata,L. castanea, L. clypeolaria, L. cf cristata and L. magnispora. Noteworthily, amatoxins were only detected in Lepiota brunneoincarnata and the newly described species L. venenata from Lepiota section Ovisporae. Both species did not contain PHD and PCD. In L. brunneoincarnata, the toxins were as follows: α-amanitin(0.516-1.981 mg/g dried specimens) was followed by β-amanitin(0.239-0.941 mg/g) and γ-amanitin(0-0.003 mg/g) in trace amounts. In L. venenata, only α-amanitin(0.176-1.289 mg/g)and γ-amanitin(0.019-0.156 mg/g) were detected.