Novel 2,5-Diarylcyclopentenone Derivatives from the Wild Edible Mushroom Paxillus involutus and Their Antioxidant Activities

Isolation and target identification of antihepatoma polyprenylphenols from the edible mushroom Suillus granulatus

Eight polyprenylphenol derivatives were isolated from the wild edible mushroom Suillus granulatus, including seven novel compounds, named suillin F-L (2-8), and one previously identified compound (1). The structures of the new compounds were elucidated using HR-ESI-MS and 1D and 2D NMR data. The absolute configuration of compound 8 was assigned based on the comparison of the experimental and calculated ECD data. All isolated compounds were evaluated for their cytotoxicity against HepG2 cancer cell lines. Compounds 1 and 3-6 demonstrated significant antitumor activity compared to the positive control (cisplatin), with IC50 values ranging from 8.19 to 13.97 μM. Furthermore, DARTS assay and LC-MS/MS analysis were used to identify HSP90AA1 as the direct target of compound 5, and the interaction between compound 5 and HSP90AA1 was verified by molecular docking.

Biological Activities of Secondary Metabolites from the Edible-Medicinal Macrofungi

Macrofungi are well-known as edible-medicinal mushrooms, which belong mostly to Basidiomycota, with a few from Ascomycota. In recent years, macrofungi have been recognized as a rich resource of structurally unique secondary metabolites, demonstrating a wide range of bioactivities, including anti-tumor, antioxidant, anti-inflammatory, antimicrobial, antimalarial, neuro-protective, hypoglycemic, and hypolipidemic activities. This review highlights over 270 natural products produced by 17 families of macrofungi covering 2017 to 2023, including their structures, bioactivities, and related molecular mechanisms.

Extraction Optimization and Antioxidant Activities of Ethanol Extract of the Brown Roll-Rim Mushroom Paxillus involutus (Agaricomycetes)

Box Behnken design (BBD) was used to optimize the extraction of Paxillus involutus (EPI) in ethanol. The optimum extraction conditions were as follows: temperature 45°C; solid:liquid ratio 1:35; time 5 h. Under these conditions, the yield of EPI was 13.57%. The antioxidant activity of EPI was evaluated in vitro, and DPPH free radical scavenging, ABTS free radical scavenging, and hydroxyl free radical scavenging effects were found to be equal to or close to that of the positive control vitamin C (VC). The antioxidant activity of EPI was next evaluated in vivo using aging mice; it was found to have appreciable effect on scavenging malonic dialdehyde (MDA) and could increase the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and total superoxide dismutase (T-SOD) in mice. Overall, EPI showed antioxidant effects in aging mice, thereby delaying aging, and has potential for application as a natural antioxidant and in medical applications.

Corrigendum: Compounds purified from edible fungi fight against chronic inflammation through oxidative stress regulation

[This corrects the article DOI: 10.3389/fphar.2022.974794.].

Natural dihydroisobenzofuran derivatives as a template for promising radical scavengers: theoretical insights into structure–activity relationships, thermochemistry and kinetics

Dihydroisobenzofuran heterocycle is a structural motif found in a number of medications with anti-tumour, anti-diabetic, and antibacterial activities. It is also found in a slew of natural substances, most notably fungus metabolites, which have been shown to possess credible radical scavenging activity. Density functional theory studies on three different derivatives were conducted to investigate their electronic structures as well as thermochemical and kinetic behaviour against ·OOH, ·OH, and ·OCH3 in biologically relevant solvents, with the goal of elucidating structure–activity relationships and discussing the potential role of the scaffolds as a template for new semisynthetic antioxidants. The importance of resonance and inductive effects, and also hydrogen bonding, has been underlined, but most importantly, it has been demonstrated that all structures have considerable scavenging potential against all studied radicals, with reactions rates close to the diffusion limit.

Compounds purified from edible fungi fight against chronic inflammation through oxidative stress regulation

Chronic inflammation is associated with various chronic diseases, including cardiovascular disease, neurodegenerative disease, and cancer, which severely affect the health and quality of life of people. Oxidative stress induced by unbalanced production and elimination of reactive oxygen species (ROS) is one of the essential risk factors for chronic inflammation. Recent studies, including the studies of mushrooms, which have received considerable attention, report that the antioxidant effects of natural compounds have more advantages than synthetic antioxidants. Mushrooms have been consumed by humans as precious nourishment for 3,000 years, and so far, more than 350 types have been identified in China. Mushrooms are rich in polysaccharides, peptides, polyphenols, alkaloids, and terpenoids and are associated with several healthy biological functions, especially antioxidant properties. As such, the extracts purified from mushrooms could activate the expression of antioxidant enzymes through the Keap1/Nrf2/ARE pathway to neutralize excessive ROS and inhibit ROS-induced chronic inflammation through the NF-κB pathway. Recently, the antioxidant properties of mushrooms have been successfully applied to treating cardiovascular disease (CAD), neurodegenerative diseases, diabetes mellitus, and cancer. The present review summarizes the antioxidant properties and the mechanism of compounds purified from mushrooms, emphasizing the oxidative stress regulation of mushrooms to fight against chronic inflammation.

Enyne diketones as substrate in asymmetric Nazarov cyclization for construction of chiral allene cyclopentenones

The Nazarov cyclization is one of the most powerful tools for the stereoselective synthesis of various cyclopentenone scaffolds. Therefore, developing the new classes substrate of Nazarov reaction is an important endeavor in synthetic chemistry. Herein, we report enyne diketones, enables diastereo- and enantioselective construction of chiral allene cyclopentenones in moderate to good yields with good enantioselectivities (up to 97% ee). Importantly, it is a typical example for asymmetric synthesis of cyclopentanones with allene moiety using Nazarov cyclisation. Mechanistic studies indicate that this metal-organo relay catalysis protocol involves a rhodium-catalyzed tandem oxonium ylide formation/[2,3]-sigmatropic rearrangement/reverse benzylic acid rearrangement, followed by organo-catalyzed asymmetric Nazarov cyclization/alkyne-to-allene isomerization to give the final chiral allene cyclopentenones.

Edible mushroom industry in China: current state and perspectives

China is one of the largest producers and exporters of wild edible fungi in the world. Cultivation mushroom production value ranks within the top five after grain, vegetable, fruit, and edible oil plantation, greater than sugar, cotton, and tobacco business. More than 40 new varieties of high market value mushrooms from our group were highlighted in this article. Mushroom cultivations have a high impact on China's poverty alleviation program, with earnings at least ten times higher than rice and corn. The products were exported to 137 countries and regions, mainly to Japan, South Korea, ASEAN, the USA, and the European Union, among these, Japan is the biggest import market for cultivated mushrooms from China. Rapid development in the market and an increased demand for edible fungi generally enhance the economy of domestic edible fungi. We are the leading research group in logical farm design that is HACCP-certified to reduce the cost of investment for agriculture, thus broadening the consumption market of edible mushrooms and forming a demand-oriented leading industry for the promotion of human health. The enterprise needs to re-examine the operation plan and the strategic thinking to improve the fundamental drivers based on the available resources of the locality. Mushrooms growing intergrate with upgraded technologies and equipment to become smart agriculture which have smart production and intelligent factories. The purpose of suitable products will not change: delicious, nutritious, healthy, and modern. KEY POINTS: • Cultivation mushroom production value ranks within the top five after grain, vegetable, fruit, and edible oil plantation, greater than sugar, cotton, and tobacco business. • Mushroom cultivations have a high impact on China's poverty alleviation program, with earnings at least ten times higher than rice and corn. • The development of transportation and industrialization of mushrooms facilitate the modernization of mushroom industry in China.

Bioactive specialised metabolites from the endophytic fungus Xylaria sp. of Cudrania tricuspidata

Fourteen undescribed compounds, including five 2,5-diarylcyclopentenones xylariaones A1-B2, seven α-pyrone derivatives xylaripyones A-G, one γ-pyrone derivative xylaripyone H, one diketopiperazine cyclo-(L-Leu-N-ethyl-L-Glu), and two known diketopiperazines, were isolated from cultures of the endophytic fungus Xylaria sp., which was separated from Cudrania tricuspidata Bureau ex Lavallée. Their structures were determined by analysing extensive spectroscopic data (HRESIMS and NMR) and electronic circular dichroism (ECD) calculations. Furthermore, these compounds were evaluated for potential antiproliferative activity against the human tumour cell lines PC3 and A549, and the results showed that xylaripyone D exhibited moderate inhibitory activity against the proliferation of PC3 cell lines with an IC₅₀ value of 14.75 μM. Meanwhile, xylariaone A3 and xylaripyone F displayed weak inhibitory effects on NO production in RAW 264.7 murine macrophages with IC₅₀ values of 49.76 and 69.68 μM, respectively.

Two new compounds from edible mushroom Sarcomyxa edulis

Chemical investigation of the edible mushroom Sarcomyxa edulis led to the isolation of one new highly degraded sterol (1), and one new β-carboline alkaloid (2), along with nine known compounds (3-11) for the first time from this mushroom. The structures of new compounds were elucidated using HR-ESI-MS data and NMR spectroscopy. In addition, anti-inflammatory activity of new compounds was evaluated against lipopolysaccharide-induced NO production in RAW 264.7 macrophages. Compound 2 exhibited a good anti-inflammatory activity with IC₅₀ value of 9.88 ± 0.48 μM, and compound 1 exhibited a weak inhibitory effect with IC₅₀ value of 71.36 ± 5.11 μM.

Novel hypoglycemic compounds from wild mushroom Paxillus involutus

Wild mushrooms are an important source of secondary metabolites possessing a broad range of biological activities. In this study, eight new compounds, named furanopaxin A-F (1-6), deoxybisinvolutone (7), and coumarinvol (8) along with two known compounds were isolated from fruiting bodies of the wild mushroom Paxillus involutus (Batsch) Fr. Their structures were established based on HR-ESI-MS and 1D and 2D NMR spectroscopic data. The results of hypoglycemic assays indicated that compounds 5-8 possessed significant α-glucosidase inhibitory activities, with IC₅₀ values ranging from 14.65 ± 1.68 to 47.55 ± 1.47 μM, and each compound could enhance glucose consumption in insulin-resistance HepG2 cells. Further analysis by molecular docking implied that compounds 5-8 could interact with the amino acid residues of α-glucosidase, supporting the hypoglycemic activity of the compounds.