Anticholinesterase and Antityrosinase Secondary Metabolites from the Fungus Xylobolus subpileatus.

Xylobolus subpileatus is a widely distributed crust fungus reported from all continents except Antarctica, although considered a rare species in several European countries. Profound mycochemical analysis of the methanol extract of X. subpileatus resulted in the isolation of seven compounds (1-7). Among them, (3ß,22E)-3-methoxy-ergosta-4,6,814,22-tetraene (1) is a new natural product, while the NMR assignment of its already known epimer (2) has been revised. In addition to a benzohydrofuran derivative fomannoxin (3), four ergostane-type triterpenes 4-7 were identified. The structure elucidation of the isolated metabolites was performed by one- and two-dimensional NMR and MS analysis. Compounds 2-7 as well as the chloroform, n-hexane, and methanol extracts of X. subpileatus were evaluated for their tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibitory properties. Among the examined compounds, only fomannoxin (3) displayed the antityrosinase property with 51% of inhibition, and the fungal steroids proved to be inactive. Regarding the potential acetylcholinesterase (AChE) inhibitory activity of the fungal extracts and metabolites, it was demonstrated that the chloroform extract and compounds 3-4 exerted noteworthy inhibitory activity, with 83.86 and 32.99%, respectively. The butyrylcholinesterase (BChE) inhibitory assay revealed that methanol and chloroform extracts, as well as compounds 3 and 4, exerted notable activity, while the rest of the compounds proved to be only weak enzyme inhibitors. Our study represents the first report on the chemical profile of basidiome of the wild-growing X. subpileatus, offering a thorough study on the isolation and structure determination of the most characteristic biologically active constituents of this species.

Isolation and Characterization of Chemical Constituents from the Poroid Medicinal Mushroom Porodaedalea chrysoloma (Agaricomycetes) and Their Antioxidant Activity.

The chemical analysis of the methanol extract of Porodaedalea chrysoloma (Fr.) Fiasson & Niemela afforded the isolation of five compounds (1-5). The first two are phenolic derivatives: methyl (E)-3-(4-methoxycar-bonylphenoxy)-acrylate (1) is a new natural product, while methyl 3-(4-methoxycarbonylphenoxy)-propionate (2) was isolated from a natural source for the first time. The triterpene steroids ergone (3), 3ß-hydroxyergosta-7,22-diene (4), and ergosterol (5) have not been previously identified in this species. The structures of the compounds were determined on the basis of NMR and MS spectroscopic analysis. The isolated fungal metabolites 1-5 were evaluated for their antioxidant activity. Compounds 1, 2, and 4 proved to possess considerable antioxidant effect in the ORAC assay with 2.21 ± 0.34, 1.58 ± 0.18, and 5.02 ± 0.47 mmol TE/g, respectively.

GIRK channel activity of Hungarian mushrooms: From screening to biologically active metabolites.

In the current study effects of fungal extracts on the G-protein-activated inwardly rectifying potassium channel (GIRK1/4) were screened using the automated patch-clamp method. 40 organic (n-hexane, chloroform, and 50% methanol) and aqueous extracts were prepared from 10 mushroom species native to Hungary. Among the examined fungal fractions of different polarities some n-hexane and chloroform extracts exerted considerable ion channel activity. One of the most active fungal species, Hypholoma lateritium was selected for further detailed examination to determine the compounds responsible for the observed pharmacological property. Evaluation of the ion channel activity of mushroom metabolites 1-10 revealed that lanosta-7,9(11)-diene-12ß,21α-epoxy-2α,3ß,24ß,25-tetraol (5) demonstrates remarkable blocking activity on GIRK current (IC50 395.1 ±â€¯31.8 nM). Investigation of the selectivity of the GIRK inhibitory effect proved that lanosta-7,9(11)-diene-12ß,21α-epoxy-2α,3ß,24ß,25-tetraol (5) has only weak inhibitory activity on hERG channel (7.9 ±â€¯2.8% at 100 µM), exerting more than three orders of magnitude lower blocking activity on hERG channel than on GIRK channel.

Isolation and Structure Determination of Antiproliferative Secondary Metabolites from the Potato Earthball Mushroom, Scleroderma bovista (Agaricomycetes).

Mycochemical examination of a methanol extract of Scleroderma bovista Fr. (Agaricomycetes) led to the isolation of 7 compounds, which were, to our knowledge, identified for the first time in this species. The chemical structures of these compounds were determined through extensive spectroscopic methods (nuclear magnetic resonance and mass spectrometry). The fungal metabolites were identified as steroids based on ergostane (compounds 1-4) and lanostane (compounds 6 and 7) skeletons, whereas compound 5 was a ceramide derivative. We evaluated the antiproliferative activity of compounds 4-7 against human cancer cell lines (HeLa, A2780, MDA-MB-231, and MCF-7) using the MTT assay. The lanostane-type derivatives (compounds 6 and 7) and ergosterol peroxide 3-glucoside (compound 4) exerted significant antiproliferative property on 1 or more human cancer cell lines.

Investigation of Antimicrobial, Antioxidant, and Xanthine Oxidase--Inhibitory Activities of Phellinus (Agaricomycetes) Mushroom Species Native to Central Europe.

Ten representative Central European phellinoid Hymenochaetaceae species (Phellinus sensu lato) were selected to examine their potential pharmacological activity. In this study 40 organic (n-hexane, chloroform, 50% methanol) and aqueous extracts with different polarities were analyzed for their antimicrobial, antioxidant, and xanthine oxidase (XO)--inhibitory properties. Fomitiporia robusta, Fuscoporia torulosa, Phellopilus nigrolimitatus, and Porodaedalea chrysoloma showed moderate antibacterial activity; Bacillus subtilis ATCC 6633, methicillin-resistant Staphylococcus aureus ATCC 43300, and Moraxella catarrhalis ATCC 43617 were the strains most susceptible to the examined fungal species. The in vitro antioxidant and XO assays demonstrated that most of the selected species possess remarkable antioxidant and XO-inhibitory activities. The water extracts in general proved to be more active antioxidants than organic extracts. In the case of F. torulosa, Ph. Nigrolimitatus, and P. chrysoloma, the results of DPPH tests correlate well with those obtained by oxygen radical absorbance capacity tests; these mushrooms presented high antioxidant activities in both assays. Future studies involving phellinoid Hymenochaetaceae species are planned, which may furnish novel results in terms of the species' pharmacological activity and the specific compounds responsible for the observed activity.

Antiproliferative Activity of Some Higher Mushrooms from Hungary against Human Cancer Cell Lines.

In the present work, aqueous and organic extracts of 16 Basidiomycetes mushrooms and 1 Ascomycetes mushroom were investigated in vitro for their antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), and MCF7 (breast epithelial adenocarcinoma) cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A total of 68 n-hexane, chloroform, 50% methanol, and water extracts of selected species were screened for their potential cell growth inhibitory activity. Our experiments revealed that 7 of 17 species demonstrated notable antiproliferative activity (at least 50% inhibition of cell proliferation) against one or more cell lines. Kuehneromyces mutabilis, Lactarius quietus, and Lentinellus cochleatus, which exerted the highest activity on cancer cells, are considered valuable species in the perspective of further mycochemical studies.

Xanthine oxidase inhibitory activity of Hungarian wild-growing mushrooms.

Mushrooms represent a remarkable and yet largely unexplored source of new, biologically active natural products. In this work, we report on the xanthine oxidase (XO) inhibitory activity of 47 wild-growing mushrooms native to Hungary. Aqueous and organic (n-hexane, chloroform, and 50% methanol) extracts of selected mushrooms from different families were screened for their XO inhibitory activities. Among the 188 extracts investigated, the chloroform and 50% methanol fractions proved to be the most effective. Some species exhibited high inhibitory activity, e.g., Hypholoma fasciculare (IC50 =67.76 ± 11.05 µg/mL), Suillus grevillei (IC50 =13.28 ± 1.58 µg/mL), and Tricholoma populinum (IC50 =85.08 ± 15.02 µg/mL); others demonstrated moderate or weak activity. Additional studies are warranted to characterize the compounds responsible for the XO inhibitory activity of mushroom extracts.

Novel ecdysteroids from Serratula wolffii.

Two new and one known ecdysteroids were identified in the methanolic extract of the roots of Serratula wolffii. The new compounds isolated were ponasterone A-22-apioside (1) and 3-epi-shidasterone (3), together with the known 3-epi-22-deoxy-20-hydroxyecdysone (2). The structures of compounds 1-3 were determined by extensive spectroscopic techniques, including one- and two-dimensional NMR methods.