Structure and Biological Activity of Ergostane-Type Steroids from Fungi

Ergosterols with rare peroxide, oxetane ring moiety, and a lactone ring from Aspergillus spectabilis and their immunosuppressive activities

Ten ergostane-type steroids, including seven undescribed ones named spectasteroids A-G, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined based on HRESIMS, NMR, ECD calculations, and single-crystal X-ray diffraction analyses. Structurally, spectasteroid A was a unique example of aromatic ergostane-type steroid that featured a rare peroxide ring moiety; spectasteroid B contained a rare oxetane ring system formed between C-9 and C-14; and spectasteroid C was an unusual 3,4-seco-ergostane steroid with an extra lactone ring between C-3 and C-9. Spectasteroids F and G specifically showed inhibitory effects against concanavalin A-induced T lymphocyte proliferation and lipopolysaccharide-induced B lymphocyte proliferation, with IC50 values ranging from 2.33 to 4.22 μM. Spectasteroid F also showed excellent antimultidrug resistance activity, which remarkable enhanced the inhibitory activity of PTX on the colony formation of SW620/Ad300 cells.

Secondary metabolites and their bioactivities from Paecilomyces gunnii YMF1.00003

Four new polyketides (1-4) and seven known compounds (5-11) including three polyketides and four sterols were isolated from the fermented extracts of Paecilomyces gunnii YMF1.00003. The new chemical structures were determined through the analysis of the nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry, and their configurations were subsequently confirmed by nuclear overhauser effect spectroscopy, the calculated electronic circular dichroism (ECD) spectra, and quantum chemical calculations of the NMR data (qcc NMR). Based on the results of pre-activity screening and compound structure target prediction, certain metabolites were assayed to evaluate their cytotoxic and protein kinase Cα inhibitory activities. Results indicated that 3β-hydroxy-7α-methoxy-5α,6α-epoxy-8(14),22E-dien-ergosta (8) exhibited potent cytotoxic activity, with half-maximal inhibitory concentration values of 3.00 ± 0.27 to 15.69 ± 0.61 μM against five tumor cells, respectively. The new compound gunniiol A (1) showed weak cytotoxic activity at a concentration of 40 μM. At a concentration of 20 μg/mL, compounds 1, 6, and 7 exhibited protein kinase Cα inhibition by 43.63, 40.93, and 57.66%, respectively. This study is the first to report steroids demonstrating good cytotoxicity and polyketides exhibiting inhibitory activity against protein kinase Cα from the extracts of P. gunnii.

Bioactive steroids from seed germination supporting fungus (Ceratobasidium GS2) of the terrestrial orchid Gymnadenia conopsea

Almost all orchids rely on mycorrhizal fungus to support their seed germination. To date, the effect of active components in mycorrhizal fungus on orchid seed germination largely remains unknown. In this study, we aimed to investigate the impact of active components found in mycorrhizal fungus on orchid seed germination. Specifically, we focused on a terrestrial orchid Gymnadenia conopsea and its host-specific seed germination supporting fungus Ceratobasidium GS2. In total, several steroids (1-7) were isolated from this fungus. Notably, compounds 1, 2, 4, and 5 exhibited significant enhancements in protocorm volume. Moreover, compounds 1-6 demonstrated strong promotion of protocorm differentiation. These findings suggest that steroids may play a crucial role in the symbiotic germination of G. conopsea seeds. Future studies should continue to explore the specific mechanisms through which these steroids exert their effects, contributing to our understanding of orchid biology and mycorrhizal interaction.

Ganoderma adspersum (Ganodermataceae): Investigation of Its Secondary Metabolites and the Antioxidant, Antimicrobial, and Cytotoxic Potential of Its Extracts

Ganoderma is a genus of wood-degrading mushrooms with medicinal importance. Most Ganoderma species have been studied extensively for their secondary metabolites, biological activities, and ecological value. In this study, the biological activities of the extracts of G. adspersum growing wild on Morus alba trees in the region of Western Thrace (Greece) were evaluated, and the petroleum ether, dichloromethanolic, and methanolic extracts were studied further for their secondary metabolites. Six substances were isolated by chromatographic (Clumn Chromatography (C.C.), High Performance Liquid Chromatography (HPLC)) and spectroscopic methods (Nuclear Magnetic Resonance (NMR)), which were classified in the following categories: (a) unsaturated fatty acids: cis-oleic acid (1); (b) sterols: ergosta-7,22-dien-3-one (2), ergosta-7,22-dien-3-ol (3), and ergosta-5,7,22-trien-3-ol (4); and (c) lanostane-type triterpenoids: applanoxidic acid G (5) and applanoxidic acid A (6). Finally, the biological activities of the extracts were estimated for their antioxidant, antimicrobial, and cytotoxic potential. The methanolic extract of G. adspersum showed the highest total antioxidant activity. The results of the antimicrobial activities indicated that all of the extracts had a minimum inhibitory concentration (MIC) ranging between 39.1 and 312.5 μg/mL. The evaluation of the cytotoxic activity of the samples showed once again that the methanolic extract was the most potent among the examined extracts, with half-maximal inhibitory concentration (IC50) values of 19.22 μg/mL (Hep2c cells), 32.9 μg/mL (RD cells), and 8.94 μg/mL (L2OB cells). Moreover, the bioactivity scores of the isolated secondary metabolites were calculated using the online computer software program Molinspiration. The compounds showed promising bioactivity scores for drug targets.

Unique Bioactives from Zombie Fungus (Cordyceps) as Promising Multitargeted Neuroprotective Agents

Cordyceps, also known as "zombie fungus", is a non-poisonous mushroom that parasitizes insects for growth and development by manipulating the host system in a way that makes the victim behave like a "zombie". These species produce promising bioactive metabolites, like adenosine, β-glucans, cordycepin, and ergosterol. Cordyceps has been used in traditional medicine due to its immense health benefits, as it boosts stamina, appetite, immunity, longevity, libido, memory, and sleep. Neuronal loss is the typical feature of neurodegenerative diseases (NDs) (Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS)) and neurotrauma. Both these conditions share common pathophysiological features, like oxidative stress, neuroinflammation, and glutamatergic excitotoxicity. Cordyceps bioactives (adenosine, N6-(2-hydroxyethyl)-adenosine, ergosta-7, 9 (11), 22-trien-3β-ol, active peptides, and polysaccharides) exert potential antioxidant, anti-inflammatory, and anti-apoptotic activities and display beneficial effects in the management and/or treatment of neurodegenerative disorders in vitro and in vivo. Although a considerable list of compounds is available from Cordyceps, only a few have been evaluated for their neuroprotective potential and still lack information for clinical trials. In this review, the neuroprotective mechanisms and safety profile of Cordyceps extracts/bioactives have been discussed, which might be helpful in the identification of novel potential therapeutic entities in the future.

A comprehensive review of secondary metabolites from the genus Agrocybe: Biological activities and pharmacological implications

The genus Agrocybe, situated within the Strophariaceae family, class Agaricomycetes, and phylum Basidiomycota, encompasses a myriad of species exhibiting significant biological activities. This review presents an integrative overview of the secondary metabolites derived from Agrocybe species, elucidating their respective biological activities and potential pharmacological applications. The metabolites under scrutiny encompass a diverse array of biological macromolecules, specifically polysaccharides and lectins, as well as a diverse group of 80 documented small molecular chemical constituents, classified into sterols, sesquiterpenes, volatile compounds, polyenes, and other compounds, their manifesting anti-inflammatory, anticancer, antioxidant, hepatoprotective, antimicrobial, and antidiabetic activities, these metabolites, in which polysaccharides exhibit abundant activities, underscore the potential of the Agrocybe genus as a valuable source of biologically active natural products. The present review emphasises the need for escalated research into Agrocybe, including investigations into the biosynthetic pathways of these metabolites, which could foster the development of novel pharmaceutical therapies to address various health challenges.

Anti-Inflammatory Ergosteroid Derivatives from the Coral-Associated Fungi Penicillium oxalicum HL-44

To obtain the optimal fermentation condition for more abundant secondary metabolites, Potato Dextrose Agar (PDA) medium was chosen for the scale-up fermentation of the fungus Penicillium oxalicum HL-44 associated with the soft coral Sinularia gaweli. The EtOAc extract of the fungi HL-44 was subjected to repeated column chromatography (CC) on silica gel and Sephadex LH-20 and semipreparative RP-HPLC to afford a new ergostane-type sterol ester (1) together with fifteen derivatives (2-16). Their structures were determined with spectroscopic analyses and comparisons with reported data. The anti-inflammatory activity of the tested isolates was assessed by evaluating the expression of pro-inflammatory factors Tnfα and Ifnb1 in Raw264.7 cells stimulated with LPS or DMXAA. Compounds 2, 9, and 14 exhibited significant inhibition of Ifnb1 expression, while compounds 2, 4, and 5 showed strong inhibition of Tnfα expression in LPS-stimulated cells. In DMXAA-stimulated cells, compounds 1, 5, and 7 effectively suppressed Ifnb1 expression, whereas compounds 7, 8, and 11 demonstrated the most potent inhibition of Tnfα expression. These findings suggest that the tested compounds may exert their anti-inflammatory effects by modulating the cGAS-STING pathway. This study provides valuable insight into the chemical diversity of ergosteroid derivatives and their potential as anti-inflammatory agents.

Steroid Components of Marine-Derived Fungal Strain Penicillium levitum N33.2 and Their Biological Activities

Genus Penicillium comprising the most important and extensively studied fungi has been well-known as a rich source of secondary metabolites. Our study aimed to analyze and investigate biological activities, including in vitro anti-cancer, anti-inflammatory and anti-diabetic properties, of metabolites from a marine-derived fungus belonging to P. levitum. The chemical compounds in the culture broth of P. levitum strain N33.2 were extracted with ethyl acetate. Followingly, chemical analysis of the extract leaded to the isolation of three ergostane-type steroid components, namely cerevisterol (1), ergosterol peroxide (2), and (3β,5α,22E)-ergosta-6,8(14),22-triene-3,5-diol (3). Among these, (3) was the most potent cytotoxic against human cancer cell lines Hep-G2, A549 and MCF-7 with IC50 values of 2.89, 18.51, and 16.47 µg/mL, respectively, while the compound (1) showed no significant effect against tested cancer cells. Anti-inflammatory properties of purified compounds were evaluated based on NO-production in LPS-induced murine RAW264.7 macrophages. As a result, tested compounds performed diverse inhibitory effects on NO production by the macrophages, with the most significant inhibition rate of 81.37 ± 1.35% at 25 µg/mL by the compound (2). Interestingly, compounds (2) and (3) exhibited inhibitory activities against pancreatic lipase and α-glucosidase enzymes in vitro assays. Our study brought out new data concerning the chemical properties and biological activities of isolated steroids from a P. levitum fungus.

Bioactive Steroids Bearing Oxirane Ring

This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.

Seco-pimarane diterpenoids and androstane steroids from an endophytic Nodulisporium fungus derived from Cyclosorus parasiticus

Five previously undescribed specialized metabolites, including three 9,11-seco-pimarane diterpenoids, nodulisporenones A-C, and two androstane steroids, nodulisporisterones A and B, together with previously described ergosterol derivatives, dankasterone A and demethylincisterol A₃, were isolated from solid cultures of the endophytic fungus Nodulisporium sp. SC-J597. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis and theoretical calculations of electronic circular dichroism spectra. Among them, nodulisporenones A and B are the first examples of seco-pimarane diterpenoids that is cyclized to form an unprecedented diterpenoid lactone scaffold and nodulisporisterones A and B represent the first normal C₁₉ androstane steroids of fungal origin. Nodulisporisterone B exhibited potent inhibitory effect on the production of NO in LPS-stimulated RAW264.7 macrophages (IC₅₀ = 2.95 μM). This compound, together with the two known ergosterol derivatives, also displayed cytotoxicity against A549, HeLa, HepG2 and MCF-7 cancer cell lines with IC₅₀ values of 5.2-16.9 μM.

Nine undescribed oxidized ergosterols from the endophytic fungus Penicillium herquei and their cytotoxic activity

A chemical investigation of the EtOAc extract of the endophytic fungus Penicillium herquei led to the isolation of nine undescribed oxidized ergosterols, penicisterols A-I (1-9), along with ten known analogs (10-19). Their structures and absolute configurations were elucidated by a combination of spectroscopic data analysis, quantum-chemical electronic circular dichroism (ECD) calculations and comparisons, [Rh₂(OCOCF₃)₄]-induced ECD experiments, DFT-calculated ¹³C chemical shifts and DP4+ probability analysis. Compound 1 was a rare example of ergosterol in which the bond between C-8 and C-9 is cleaved to form an enol ether. Moreover, compound 2 possessed a rare (2,5-dioxo-4-imidazolidinyl)-carbamic acid ester group substituted at C-3. All undescribed oxidized ergosterols (1-9) were evaluated for their cytotoxic activity against five cancer cell lines including 4T1 (mouse breast carcinoma), A549 (human pulmonary carcinoma), HCT-116 (human colorectal carcinoma), HeLa (human cervical carcinoma) and Hepg2 (human hepatoma carcinoma) cells. Compounds 2 and 3 displayed moderate cytotoxic activity against 4T1, A549 and HeLa cells, with IC₅₀ values ranging from 17.22 to 31.35 μM.

Bioactive and unusual steroids from Penicillium fungi

Penicillium fungi are represented by various species and can be found worldwide and thrive in a range of environments, such as in the soil, air, and indoors, and in marine environments, as well as food products. Chemical investigation of species of this genus has led to the discovery of compounds from several structural classes with varied bioactivities. As an example, this genus has been a source of bioactive and structurally unusual steroids. The scope of this short review is to cover specialized metabolites of the steroid class and the cytotoxic, antimicrobial, anti-inflammatory as well as phytotoxic activities of these compounds. Other steroids that possess unusual structures, with significant bioactivity yet to determined, will also be discussed to further demonstrate the structural diversity of this compound class from Penicillium fungi, and hopefully inspire the further exploration of such compounds to uncover their activity.

Chemical Constituents of the Mushroom Dictyophora indusiata and Their Anti-Inflammatory Activities

As an edible and medicinal fungus, Dictyophora indusiata is well-known for its morphological elegance, distinctive taste, high nutritional value, and therapeutic properties. In this study, eighteen compounds (1-18) were isolated and identified from the ethanolic extract of D. indusiata; four (1-4) were previously undescribed. Their molecular structures and absolute configurations were determined via a comprehensive analysis of spectroscopic data (1D/2D NMR, HRESIMS, ECD, and XRD). Seven isolated compounds were examined for their anti-inflammatory activities using an in vitro model of lipopolysaccharide (LPS)-simulated BV-2 microglial cells. Compound 3 displayed the strongest inhibitory effect on tumor necrosis factor-α (TNF-α) expression, with an IC₅₀ value of 11.9 μM. Compound 16 exhibited the highest inhibitory activity on interleukin-6 (IL-6) production, with an IC₅₀ value of 13.53 μM. Compound 17 showed the most potent anti-inflammatory capacity by inhibiting the LPS-induced generation of nitric oxide (NO) (IC₅₀: 10.86 μM) and interleukin-1β (IL-1β) (IC₅₀: 23.9 μM) and by significantly suppressing induced nitric oxide synthase (iNOS) and phosphorylated nuclear factor-kappa B inhibitor-α (p-IκB-α) expression at concentrations of 5 μM and 20 μM, respectively (p < 0.01). The modes of interactions between the isolated compounds and the target inflammation-related proteins were investigated in a preliminary molecular docking study. These results provided insight into the chemodiversity and potential anti-inflammatory activities of metabolites with small molecular weights in the mushroom D. indusiata.

Ergosterol Isolated from Antrodia camphorata Suppresses LPS-Induced Neuroinflammatory Responses in Microglia Cells and ICR Mice

Inflammation caused by microglial activation is important in neurodegenerative diseases. In this research, we tried to identify safe and effective anti-neuroinflammatory agents by screening a natural compounds library and found that Ergosterol can inhibit the nuclear factor kappa-light-chain enhancer of the activated B cells (NF-κB) pathway induced by lipopolysaccharide (LPS) in microglia cells. Ergosterol has been reported to be an effective anti-inflammatory agent. Nevertheless, the potential regulatory role of Ergosterol in neuroinflammatory responses has not been fully investigated. We further investigated the mechanism of Ergosterol that regulates LPS-induced microglial activation and neuroinflammatory reactions both in vitro and in vivo. The results showed that Ergosterol can significantly decrease the pro-inflammatory cytokines induced by LPS in BV2 and HMC3 microglial cells, possibly by inhibiting the NF-κB, protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, we treated Institute of Cancer Research (ICR) mice with a safe concentration of Ergosterol following LPS injection. Ergosterol treatment significantly decreased microglial activation-associated ionized calcium-binding adapter molecule-1 (IBA-1), NF-κB phosphorylation, and pro-inflammatory cytokine levels. Moreover, Ergosterol pretreatment clearly reduced LPS-induced neuron damage by restoring the expression of synaptic proteins. Our data may provide insight into possible therapeutic strategies for neuroinflammatory disorders.

The Anti-Candida Activity of Tephrosia apollinea Is More Superiorly Attributed to a Novel Steroidal Compound with Selective Targeting

Tephrosia is widely distributed throughout tropical, subtropical, and arid regions. This genus is known for several biological activities, including its anti-Candida activity, which is mainly attributed to prenylated flavonoids. The biological activities of most Tephrosia species have been studied, except T. apollinea. This study was conducted to investigate the underlying anti-Candida activity of T. apollinea, wildly grown in the United Arab Emirates (UAE). The T. apollinea plant was collected, dried, and the leaves were separated. The leaves were ground and extracted. The dried extract was subjected to successive chromatography to identify unique phytochemicals with a special pharmacological activity. The activity of the compound was validated by homology modeling and molecular docking studies. A novel steroidal compound (ergosta-6, 8(14), 22, 24(28)-tetraen-3-one) was isolated and named TNS. In silico target identification of TNS revealed a high structural similarity with the Candida 14-α-demethylase enzyme substrate. The compound exhibited a significant anti-Candida activity, specifically against the multi-drug-resistant Candida auris at MIC₅₀, 16 times less than the previously reported prenylated flavonoids and 5 times less than the methanol extract of the plant. These findings were supported by homology modeling and molecular docking studies. TNS may represent a new class of Candida 14-α-demethylase inhibitors.

Ergostane-Type Sterols From Several Cordyceps Strains

Ergosterol is an essential component for fungi, including entomopathogenic fungi like Cordyceps. Cordyceps has been used as a traditional medicine in Japan and China and possesses various unique ergostane-type sterols, those exhibit bioactivities. In this manuscript, we reported the isolation of 2 new ergostane-type sterols, 1 and 2 along with ten sterols (3-12) from 7 strains of Cordyceps related fungal strains, Cordyceps takaomontana NBRC 101754, Metarhizium owariense NBRC 33258, Polycephalomyces formosus NBRC 109994, Cordyceps tuberculata NBRC 106948, Cordyceps tenuipes NBRC 108997, Cordyceps sp. NBRC 106954, and Tolypocladium paradoxum NBRC 106958 collected fruiting bodies of Ophiocordyceps heteropoda. In addition, the antitrypanosomal activity and antimicrobial activity of isolates were tested to find 6 showed the antitrypanosomal activity, and the minimum inhibitory concentration (MIC) value was confirmed as 1.41 µg/mL. In the antimicrobial assay, the MIC value of 8 against methicillin-resistant Staphylococcus aureus was determined to be 3.1 µg/mL.