Biochemical Characterization and Bioactive Properties of Boletus edulis (Agaricomycetes) from Serbia

The porcini mushroom, Boletus edulis, is an edible and medicinal ectomycorrhizal fungus belonging to the phylum Basidiomycota. In this study, we investigated the chemical composition and bioactive properties of its methanolic and acetonic extracts. Chemical characterization was performed using high performance liquid chromatography and gas chromatography coupled with mass spectroscopy. The most abundant components were potassium among elements (ICP-OES), chlorogenic acid among polyphenols (ion chromatography), malic acid among organic acids (UH-PLC-DAD-MS/MS), trehalose among carbohydrates (HPAEC-PAD), and palmitic acid among fatty acids (GC-MS). The antimicrobial activity, assessed by the microdilution method, showed minimum inhibitory concentration (MIC) values ranging from 1.25 to 40 mg/mL. Antioxidative activity was assessed spectrophotometrically using 1,1-diphenyl-2-picryl-hydrazil (DPPH) (IC50: 6.85 μg/mL and 614.23 μg/mL) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays (IC50: 8.33 μg/mL and 728.30 μg/mL) for methanolic and acetonic extracts, respectively, along with the reducing power assay (absorbance range 0.122-0.881). Additionally, total phenolic and flavonoid content was determined using Folin-Ciocalteu reagent and aluminum chloride method. The total content of phenolic compounds was 34.754 μg pyrocatechol equivalents (PE)/mg, and 35.403 μg PE/mg, and flavonoid content was 1.466 μg rutin equivalents (RE)/mg and 0.915 μg RE/mg for methanolic and acetonic extracts, respectively. The antidiabetic effect of the extracts was tested by the α-amylase (IC50 were 64.929 μg/mL and 71.505 μg/mL for methanolic and acetonic extract) and α-glucosidase assays (IC50 were 264.310 μg/mL and 725.151 μg/mL for methanolic and acetonic extract). The neuroprotective potential was investigated by assessing acetylcholinesterase inhibition (the results ranged from 5.40% to 43.54%). These results suggest that B. edulis has significant potential for biopharmaceutical applications.