A new research article published in Biological Research on 11 September 2026 reports that the metabolite profile of Amanita muscaria fruiting bodies collected in the forests of central Poland varied significantly with the species of symbiotic tree, the month of harvest and the weather conditions of the year.
The study, led by Lidia Szwajkowska-Michałek with colleagues including Kinga Stuper-Szablewska, analyzed the content and composition of phenolic compounds, flavonoids, coumarins, pigments and neuroactive secondary metabolites in fly agaric fruiting bodies. Samples were collected in August and September of 2022 and 2023 from two sites in the Wielkopolska region: one under pine trees and one under birch trees. In total, the researchers determined 15 phenolic compounds as well as groups of flavonoids and other bioactive metabolites, including ergosterol.
The central aim was to evaluate how environmental factors, such as the type of symbiotic tree, seasonal differences and interannual variation in temperature and rainfall, affect the biosynthesis of these metabolites. Fly agaric forms mycorrhizal partnerships with forest trees, so the identity of the host tree is one of the defining features of each collection site.
The results showed significantly higher concentrations of most analyzed compounds in fruiting bodies collected under pine trees, particularly in 2023, a year characterized by higher temperatures and lower rainfall. According to the authors, mycorrhiza with pine and the warmer weather of 2023 favored increased synthesis of protective compounds, suggesting that environmental stress may stimulate the fungus’s production of certain metabolites.
Seasonal variation was also evident. Higher concentrations of phenols and flavonoids were found in samples collected in August, while ergosterol and secondary pigments increased in September. The researchers interpret this pattern as reflecting shifts in metabolic activity and fruiting body maturation over the course of the fruiting season.
Coumarins told a similar story. These compounds were more abundant in pine-associated samples, which the authors link to enhanced production of protective metabolites under stress conditions. Together with the phenolic findings, this points to the tree partner and the weather of a given year as jointly shaping the defensive chemistry of the fruiting bodies.
The neuroactive alkaloids that make fly agaric famous were also tracked. Toxic alkaloids such as ibotenic acid and muscimol were present at higher levels in pine-associated fruiting bodies, although their concentrations varied seasonally. The study reports these as measured concentrations in collected samples rather than as any assessment of effects in humans.
Statistical analysis confirmed that both the year and the habitat had significant effects on metabolite content, with clear differences in profiles between the two sites and between the two years. This means that the observed patterns were not simply random variation but were statistically associated with the collection conditions.
The authors conclude that the species of symbiotic tree and the weather conditions, defined by the year and month of collection, significantly influence the biosynthesis of phenolic compounds, flavonoids and coumarins in A. muscaria fruiting bodies. They further suggest that total phenolic content and antioxidant activity measured by the ABTS radical assay can serve as indicators of environmental stress and the antioxidant potential of fly agaric fruiting bodies.
Beyond the specific findings for one mushroom species, the study argues that seasonal monitoring, comparing August and September collections, provides valuable information on the metabolic dynamics of fungi and may be useful in the search for bioactive compounds.
Subject of Research: How tree species, harvest date and weather influence the bioactive metabolites of Amanita muscaria fruiting bodies
Article Title: Characteristics of biocomponents of Amanita muscaria (L.) Lam. fruit bodies collected in the forests of central Poland depending on the tree species, harvest date and weather conditions
Article References: Szwajkowska-Michałek, L., Graczyk, M., Przybylska-Balcerek, A., Niedziela, G., Łakomy, P., & Stuper-Szablewska, K. (2026). Characteristics of biocomponents of Amanita muscaria (L.) Lam. fruit bodies collected in the forests of central Poland depending on the tree species, harvest date and weather conditions. Biological Research. https://doi.org/10.1186/s40659-026-00722-w
Image Credits: AI Generated
DOI: 10.1186/s40659-026-00722-w
Keywords: Amanita muscaria, fly agaric, mycorrhiza, phenolic compounds, flavonoids, coumarins, ergosterol, ibotenic acid, muscimol, antioxidant activity, Wielkopolska, secondary metabolites
News Source: Bethany Barker. (October 29, 2026). Fly agaric chemistry shifts with tree partners, seasons and weather in Polish forests. Scienmag.
