Phylogenetic and chemical studies in the potential psychotropic species complex of Psilocybe atrobrunnea with taxonomic and nomenclatural notes
Persoonia - Molecular Phylogeny and Evolution of Fungi – November 26, 2014
Source: OpenAlex
Summary
Psilocybin and psilocin, potent psychedelic alkaloids, were detected for the first time in the fungus *Psilocybe medullosa*. Investigating five *Psilocybe* species using four molecular markers, phylogenetic analysis reclassified *P. laetissima* into the *Leratiomyces* genus. Intriguingly, *P. atrobrunnea* showed no psilocybin or psilocin, even with tryptamine-rich media, suggesting a lost biosynthesis pathway for these psychedelics. This advances understanding of fungal biology, chemical synthesis of alkaloids, and plant and fungal interactions within the genus.
Abstract
Five Psilocybe species with unresolved systematic position ( P. atrobrunnea , P. laetissima , P. medul- losa , P. pelliculosa , and P. silvatica ) were investigated using four molecular markers (EF1-α, ITS, LSU, and IGS). Phylogenetic analysis revealed that with the exception of P. laetissima , which is now rightfully classified in the genus Leratiomyces , all investigated species belong to Psilocybe sect. Psilocybe . For the first time, psychotropic compounds psilocin and psilocybin were detected in P. medullosa using gas chromatography-mass spectrometry. On the contrary, neither psilocin, nor psilocybin was detected in P. atrobrunnea and negative results were also obtained from mycelia grown in vitro on tryptamine/tryptophan-amended media. These results strongly suggest that biosynthesis of these alkaloids was lost in P. atrobrunnea . With the exception of minor differences detected in EF1-α marker, all sequences of American and European collections of P. atrobrunnea were identical. On the other hand, a thorough nomenclatural study revealed that the name P. atrobrunnea must be considered dubious; the oldest available candidate name, P. fuscofulva , was therefore adopted. The molecular data suggests that morphologically identical American P. silvatica and European P. medullosa likely represent distinct species; epitypes of both taxa were therefore designated.