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

Abstract Background This study analyzed the content and composition of phenolic compounds, flavonoids, coumarins, pigments, and neuroactive secondary metabolites in fly agaric ( Amanita muscaria ) fruiting bodies collected in August and September 2022 and 2023 from two sites: under pine trees and under birch trees in the Wielkopolska region. A total of 15 phenolic compounds, as well as groups of flavonoids and other bioactive metabolites, including ergosterol, were determined. The study aimed 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. Results The results showed significantly higher concentrations of most analyzed compounds in fruiting bodies collected under pine trees, particularly in 2023, which had higher temperatures and lower rainfall. Seasonal variation was evident: higher concentrations of phenols and flavonoids were found in August, while ergosterol and secondary pigments increased in September, suggesting shifts in metabolic activity and fruiting body maturation. Coumarins were also more abundant in pine-associated samples, indicating enhanced production of protective metabolites under stress conditions. Toxic alkaloids such as ibotenic acid and muscimol were present at higher levels in pine fruiting bodies, though their concentrations varied seasonally. Statistical analysis confirmed that both the year and habitat had significant effects on metabolite content, with clear differences in profiles between sites and years. Conclusion The study results confirm that the species of symbiotic tree and weather conditions (year and month of collection) significantly influence the biosynthesis of phenolic compounds, flavonoids, and coumarins in A. muscaria fruiting bodies. Mycorrhiza with pine and the warmer weather of 2023 favored increased synthesis of protective compounds. Seasonal monitoring (August vs. September) provides valuable information on the metabolic dynamics of fungi and may be useful in the search for bioactive compounds. Furthermore, total phenolic content (TPC) and antioxidant activity (ABTS ·+ ) can serve as indicators of environmental stress and the antioxidant potential of fly agaric fruiting bodies.