Injury‐Triggered Blueing Reactions of Psilocybe “Magic” Mushrooms

Abstract

Upon injury, psychotropic psilocybin‐producing mushrooms instantly develop an intense blue color, the chemical basis and mode of formation of which has remained elusive. We report two enzymes from Psilocybe cubensis that carry out a two‐step cascade to prepare psilocybin for oxidative oligomerization that leads to blue products. The phosphatase PsiP removes the 4‐O‐phosphate group to yield psilocin, while PsiL oxidizes its 4‐hydroxy group. The PsiL reaction was monitored by in situ 13C NMR spectroscopy, which indicated that oxidative coupling of psilocyl residues occurs primarily via C‐5. MS and IR spectroscopy indicated the formation of a heterogeneous mixture of preferentially psilocyl 3‐ to 13‐mers and suggest multiple oligomerization routes, depending on oxidative power and substrate concentration. The results also imply that phosphate ester of psilocybin serves a reversible protective function.

Taking Different Roads: l‐Tryptophan as the Origin of Psilocybe Natural Products

“…[39] The sequence involves psilocybin dephosphorylation to psilocin, catalyzed by the phosphatase PsiP and followed by immediate oxidative coupling by the laccase PsiL. This reaction sequence results in formation of a heterogeneous mixture of psilocyl 3‐ to 13‐mers, coupled preferentially via carbons 5 and 7 of the indole nucleus [38a] …”

“…These are substance families of outstanding ecological importance that make tissue resistant to microbial attack and damage, e. g., by light [40] . Like tannins, the blue oligomers precipitate proteins [38a] . In addition, various tannins are assumed to exert defensive purposes as they generate reactive oxygen species [41] …”

Chemistry and Toxicology of Major Bioactive Substances in Inocybe Mushrooms

“…Whereas, freeze-dried mushrooms will remain active after being stored for more than two years at −5 °C [ 43 ]. Cytochrome oxidase oxidizes the dephosphorization of psilocybin to produce the blue product, and hallucinogenic mushrooms that contain the toxin often turn blue after being picked [ 44 ]. So, we can identify the hallucinogenic mushroom by this way.…”

Structure Elucidation and Spectroscopic Analysis of Chromophores Produced by Oxidative Psilocin Dimerization

“…In bruised or injured Psilocybe mushrooms, 2 is dephosphorylated as well to 1 , whose indolic 4‐OH group is subsequently oxidized. This short cascade, catalyzed by the phosphatase PsiP and the laccase PsiL, prepares 2 via 1 for instant oligomerization into a heterogeneous quinoid set of compounds that accounts for the distinctive blue hue of Psilocybe fruiting bodies [3] . Given their protein‐precipitating and radical oxidation properties, these oligomers may add a possible second layer of bioactivity – beyond the receptor‐binding nature of monomeric 1 – that perhaps protects the fungus from feeding invertebrates.…”

“…Despite numerous efforts to identify the main blue chromophore in 1 oligomerization, [4,5] the structure(s) that confer the hue on bruised Psilocybe mushrooms had been elusive, as was the mechanism by which the colored matter is formed. From previous mass spectrometry and NMR‐based studies, the 5,5’‐coupled product was initially hypothesized to contribute the blue color, given that coupling at the C‐5 position was the major reaction in the investigated enzymatic oxidation of 1 [3] . Furthermore, literature on analogous chromophores plausibly suggested a rather reddish color for the 7,7’‐coupled quinoid dimers [6] .…”