Matsutakone and Matsutoic Acid, Two (Nor)steroids with Unusual Skeletons from the Edible Mushroom Tricholoma matsutake

Ganonorsterone A, a norsteroid from the medicinal fungus Ganoderma lingzhi

Phytochemical investigation on the fruiting bodies of the medicinal fungus Ganoderma lingzhi led to the isolation of a new norsteroid, namely ganonorsterone A (1), together with one known steroid, cyathisterol (2). The structure and absolute configuration of compound 1 were assigned by extensive analysis of MS, NMR data, and quantum-chemical calculations including electronic circular dichroism (ECD) and calculated 13C NMR-DP4+ analysis. Bioassay results showed that compound 1 displayed moderate inhibition on NO production in RAW 264.7 macrophages.

Ten ring-B aromatized ergosterols from Aspergillus spectabilis

Spectasterols F-O (1-10), ten interesting ergosterols with an aromatized B ring, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), nuclear magnetic resonance (NMR) spectroscopy, single-crystal X-ray diffraction analyses, and electronic circular dichroism (ECD) calculations. Structurally, these aromatic ergosterols feature versatile side chains. Notably, compound aromatic ergosterols featured versatile side chains, and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and C-24. All compounds were evaluated for their neuroprotective activities, with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells.

Psathrosterols C-E, highly conjugated ergosterol derivatives from Psathyrella rogueiana with anti-inflammatory and immunosuppressive activity

Three new ergosterols featuring with a highly conjugated ring system, psathrosterols C-E (1-3), have been isolated from the fungus Psathyrella rogueiana. The structures with the absolute configurations were elucidated by means of spectroscopic methods and single crystal X-ray diffraction. Compounds 1-3 exhibit inhibitory activity against NO production with IC50 values ranging from 8.4 to 21.8 μM. Compound 1 inhibits the LPS-induced proliferation of B lymphocyte cells with an IC50 value of 12.3 μM.

Controllable skeletal reorganizations in natural product synthesis

Covering: 2016 to 2023The synthetic chemistry community is always in pursuit of efficient routes to natural products. Among the many available general strategies, skeletal reorganization, which involves the formation, cleavage, and migration of C-C and C-heteroatom bonds, stands out as a particularly useful approach for the efficient assembly of molecular skeletons. In addition, it allows for late-stage modification of natural products for quick access to other family members or unnatural derivatives. This review summarizes efficient syntheses of steroid, terpenoid, and alkaloid natural products that have been achieved by means of this strategy in the past eight years. Our goal is to illustrate the strategy's potency and reveal the spectacular human ingenuity demonstrated in its use and development.

Two highly conjugated ergosterols from the fungus Psathyrella rogueiana and their anti-inflammatory activity

Two previously undescribed ergosterols containing a highly conjugated ring system, psathrosterols A and B (1 and 2), have been isolated from the fungus Psathyrella rogueiana. Their structures with absolute configurations were established by extensive spectroscopic methods, as well as single crystal X-ray diffraction. Compounds 1 and 2 showed inhibitory activity against NO production with IC50 values of 22.3 and 16.4 μM, respectively.

Putting the Puzzle Together To Get the Whole Picture: Molecular Basis of the Affinity of Two Steroid Derivatives to Acetylcholinesterase

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that has no cure because its etiology is still unknown, and its main treatment is the administration of acetylcholinesterase (AChE) inhibitors. The study of the mechanism of action of this family of compounds is critical for the design of new more potent and specific inhibitors. In this work, we study the molecular basis of an uncompetitive inhibitor (compound 1, 2β, 3α-dihydroxy-5α-cholestan-6-one disulfate), which we have proved to be a peripheral anionic site (PAS)-binding AChE inhibitor. The pipeline designed in this work is key to the development of other PAS inhibitors that not only inhibit the esterase action of the enzyme but could also modulate the non-cholinergic functions of AChE linked to the process of amylogenesis. Our studies showed that 1 inhibits the enzyme not simply by blocking the main gate but by an allosteric mechanism. A detailed and careful analysis of the ligand binding position and the protein dynamics, particularly regarding their secondary gates and active site, was necessary to conclude this. The same analysis was executed with an inactive analogue (compound 2, 2β, 3α-dihydroxy-5α-cholestan-6-one). Our first computational results showed no differences in affinity to AChE between both steroids, making further analysis necessary. This work highlights the variables to be considered and develops a refined methodology, for the successful design of new potent dual-action drugs for AD, particularly PAS inhibitors, an attractive strategy to combat AD.

Multiple Metabolites Derived from Mushrooms and Their Beneficial Effect on Alzheimer's Diseases

Mushrooms with edible and medicinal potential have received widespread attention because of their diverse biological functions, nutritional value, and delicious taste, which are closely related to their rich active components. To date, many bioactive substances have been identified and purified from mushrooms, including proteins, carbohydrates, phenols, and vitamins. More importantly, molecules derived from mushrooms show great potential to alleviate the pathological manifestations of Alzheimer's disease (AD), which seriously affects the health of elderly people. Compared with current therapeutic strategies aimed at symptomatic improvement, it is particularly important to identify natural products from resource-rich mushrooms that can modify the progression of AD. This review summarizes recent investigations of multiple constituents (carbohydrates, peptides, phenols, etc.) isolated from mushrooms to combat AD. In addition, the underlying molecular mechanisms of mushroom metabolites against AD are discussed. The various mechanisms involved in the antiAD activities of mushroom metabolites include antioxidant and anti-neuroinflammatory effects, apoptosis inhibition, and stimulation of neurite outgrowth, etc. This information will facilitate the application of mushroom-derived products in the treatment of AD. However, isolation of new metabolites from multiple types of mushrooms and further in vivo exploration of the molecular mechanisms underlying their antiAD effect are still required.

Biogenetic space-guided synthesis of rearranged terpenoids

Natural product chemistry is constantly challenged by newly discovered, complex molecules. Elements of complexity arise from unprecedented frameworks, with a large amount of densely packed stereogenic centres and different functional groups along with a generally high oxidation state. As a prime example, rearranged triterpenoids possess all these elements. For their total synthesis, a limit of what is considered sensible in terms of steps and yield is frequently reached. As an alternative, semisynthetic approaches have gained a great amount of attention in recent years. In this featured article, we present our and others' contributions towards the development of efficient and economic syntheses of complex terpenoid natural products and elaborate on the underlying rationale of biogenetic space-guided synthetic analysis.

Aromatic Polyketides from the Mangrove-Derived Streptomyces sp. SCSIO 40069

A chemical investigation of Streptomyces sp. SCSIO 40069 resulted in the isolation of a series of aromatic polyketides with rare skeletons, including five new compounds RM18c-RM18g (1-5) and three known ones (6-8). Their structures and absolute configurations were determined by diverse methods, including HRMS and NMR spectra, chemical reaction, Snatzke's method, quantum mechanical-nuclear magnetic resonance (QM-NMR), and X-ray crystallographic analysis. Compounds 1, 2, 4b, and 8 displayed moderate or weak antibacterial activities.

Constructing a Myxobacterial Natural Product Database to Facilitate NMR-Based Metabolomics Bioprospecting of Myxobacteria

Myxobacteria are fascinating prokaryotes featuring a potent capacity for producing a wealth of bioactive molecules with intricate chemical topology as well as intriguing enzymology, and thus it is critical to developing an efficient pipeline for bioprospecting. Herein, we construct the database MyxoDB, the first public compendium solely dedicated to myxobacteria, which enabled us to provide an overview of the structural diversity and taxonomic distribution of known myxobacterial natural products. Moreover, we demonstrated that the cutting-edge NMR-based metabolomics was effective to differentiate the biosynthetic priority of myxobacteria, whereby MyxoDB could greatly streamline the dereplication of multifarious known compounds and accordingly speed up the discovery of new compounds. This led to the rapid identification of a class of linear di-lipopeptides (archangimins) and a rare rearranged sterol (corasterol) that were endowed with unique chemical architectures and/or biosynthetic enzymology. We also showcased that NMR-based metabolomics, MyxoDB, and genomics can also work concertedly to accelerate the targeted discovery of a polyketidic compound pyxipyrrolone C. All in all, this study sets the stage for the discovery of many more novel natural products from underexplored myxobacterial resources.

Tricholosterols A-D, four new ergosterol derivatives from the mushroom Tricholoma terreum

Four ergosterol derivatives, named tricholosterols A-D (1-4), have been isolated from the fruiting bodies of Tricholoma terreum. Their chemical structures have been determined using a combination of spectroscopic analysis as well as computational methods. Compound 1 possesses a rare D-ring opening ergosterol skeleton, while compounds 2-4 are rare degraded ergosterols. Compounds 1 and 4 exhibited moderate inhibitory activity against NO production with IC₅₀ values of 27.6 and 31.8 μM, respectively. This is the first report of steroids from T. terreum.

Polyketides with antimicrobial activities from Penicillium canescens DJJ-1

Two undescribed polyketides canecines A-B, one unreported cyclopentenone canecine C, together with 12 known compounds were isolated from an extract of the fungus Penicillium canescens DJJ-1. Their structures were elucidated by detailed analysis of spectroscopic data, NMR calculations with dJ-DP4 or DP4+, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or X-crystallography. Canecine A was a grisan polyketide featuring a dimethyltetrahydro-4H-furo[2,3-b]pyran. Canecine A exhibited significant inhibitory activity against Candida albicans with an MIC value of 1 μg/mL and showed inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages. These results enrich the structural diversities of polyketides from endophytic fungi.

Secondary Metabolites from Fungi-In Honor of Prof. Dr. Ji-Kai Liu's 60th Birthday

It is our pleasure and privilege to serve as Guest Editors for this Special Issue of the Journal of Fungi in honor of Professor Ji-Kai Liu's 60th birthday [...].

Cadinane sesquiterpenoids from the fungus Antrodiella albocinnamomea and their inhibitory activity against nitric oxide production

Seven previously undescribed cadinane sesquiterpenoids, albocinnamins A‒G, were isolated from the fungus Antrodiella albocinnamomea. Their structures with absolute configurations were elucidated on the basis of extensive spectroscopic methods, as well as single crystal X-ray diffraction. Cadinane sesquiterpenoids were reported from A. albocinnamomea for the first time. All of these sesquiterpenoids possess an unusual ether ring with minor modifications. Albocinnamins D and G showed certain inhibitory activities against nitric oxide production in LPS-activated RAW264.7 macrophages with IC₅₀ values of 26.1 and 19.2 μM, respectively.

Structure and Biological Activity of Ergostane-Type Steroids from Fungi

Mushrooms are known not only for their taste but also for beneficial effects on health attributed to plethora of constituents. All mushrooms belong to the kingdom of fungi, which also includes yeasts and molds. Each year, hundreds of new metabolites of the main fungal sterol, ergosterol, are isolated from fungal sources. As a rule, further testing is carried out for their biological effects, and many of the isolated compounds exhibit one or another activity. This study aims to review recent literature (mainly over the past 10 years, selected older works are discussed for consistency purposes) on the structures and bioactivities of fungal metabolites of ergosterol. The review is not exhaustive in its coverage of structures found in fungi. Rather, it focuses solely on discussing compounds that have shown some biological activity with potential pharmacological utility.

Insights into health promoting effects and myochemical profiles of pine mushroom Tricholoma matsutake

Tricholoma matsutake (TM) is a valuable edible mushroom that has attracted increasing attention due to its potential medicinal values and functional uses. However, the chemical composition and molecular mechanisms behinds TM are not specifically summarized yet. Hence, this review aims to systematically analyze the research progress on the characterization of chemical compositions and the reported health effects of TM in the last 20 years. The myochemical profiles of TM consist of proteins with amino acids, fatty acids, nucleic acids with their derivatives, polysaccharides, minerals, volatile components, phenolic compounds, and steroids. The bioactive substances in TM exert their health effects mainly by regulating body immunity and restoring the balance of the redox system. NF-κB signaling pathway and its downstream cytokines such as TNF-α and IL-6 are the key molecular mechanisms. In addition, MAPK, PI3K-Akt, and JAK-STAT are also involved. NF-κB, MAPK, and PI3K-Akt are also highly related to cancer regulation and thus TM has great anticancer potential. Considering that most studies have only investigated the dosage and inhibition rate of TM on cancer cell lines, more extensive studies need to focus on the specific molecular mechanisms behind these anticancer effects in the future.

Aspersteroids A-C, Three Rearranged Ergostane-type Steroids from Aspergillus ustus NRRL 275

Aspersteroid A (1), a highly rearranged 1(10 → 6)-abeo-18,22-cyclosterol, together with two new 18,22-cyclosterols (2 and 3), was isolated from the culture extract of Aspergillus ustus NRRL 275. Their structures were determined by spectroscopic analysis, X-ray diffraction, modified Mosher's method, and Rh2(OCOCF3)4-induced electronic circular dichroism experiments. Compound 1 represents a new carbon skeleton with an uncommon 6/6/6/5/5 ring system, which is presumably biosynthesized from A-ring scission, double 1,2-shifts, and C-18/C-22 cyclization. Compound 1 exhibited potent immunosuppressive and antimicrobial activities.

Pardinumones A-D: Antibacterial Polyketide-Amino Acid Derivatives from the Mushroom Tricholoma pardinum

Four polyketide-amino acid derivatives, pardinumones A-D (1-4), were isolated from the wild mushroom Tricholoma pardinum. Their structures together with absolute configurations were characterized by means of spectroscopic data analyses, as well as calculated electronic circular dichroism (ECD) and NMR with sorted training set (STS) protocol analysis. Compounds 1-4 exhibited antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli with MIC values in the range of 6.25-50 μg/mL.

Contemporary advancements in the semi-synthesis of bioactive terpenoids and steroids

Many natural products have intriguing biological properties that arise from their fascinating chemical structures. However, the intrinsic complexity of the structural skeleton and the reactive functional groups on natural products pose tremendous challenges to chemical syntheses. Semi-synthesis uses chemical compounds isolated from natural sources as the starting materials to produce other novel compounds with distinct chemical and medicinal properties. In particular, advancements in various types of sp3 C-H bond functionalization reactions and skeletal rearrangement methods have contributed to the re-emergence of semi-synthesis as an efficient approach for the synthesis of structurally complex bioactive natural products. Here, we begin with a brief discussion of several bioactive natural products that were obtained via a semi-synthetic approach between 2008 and 2015 and we then discuss in-depth contemporary advancements in the semi-synthesis of bioactive terpenoids and steroids reported during 2016-2020.

Structures, Chemical Conversions, and Cytotoxicity of Tricholopardins C and D, Two Tricholoma Triterpenoids from the Wild Mushroom Tricholoma pardinum

Two undescribed Tricholoma triterpenoids, namely tricholopardins C (1) and D (2), were isolated from the wild mushroom Tricholoma pardinum. Their structures with absolute configurations were elucidated by spectroscopic methods, as well as the single crystal X-ray diffraction. Compounds 1 and 2 were further obtained by chemical conversions from the known analogues. Compound 1 showed significant cytotoxicity to MCF-7 and Hela cell lines with IC₅₀ values of 4.7 μM and 9.7 μM, respectively. Its mechanism of inducing MCF-7 cell apoptosis was studied briefly.

Uncommon Diterpenoids from the South China Sea Soft Coral Sinularia humilis and Their Stereochemistry

The chemical investigation of the South China Sea soft coral Sinularia humilis has resulted in the isolation of a library of diverse diterpenoids, including four new cembranoids, namely, humilisins A-D (1-4), two new uncommon diterpenoids possessing a tetradecahydrocyclopenta[3',4']cyclobuta[1',2':4,5]cyclonona[1,2-b]oxirene ring system, namely, humilisins E and F (5 and 6), and eight known related compounds (7-14). Humilisin A (1) is the first cembranoid with an ether linkage between C-3 and C-7. The structures and absolute configurations of 1-8 were determined by extensive spectroscopic data analyses, chemical reactions, and a series of quantum chemical calculations including quantum mechanical-nuclear magnetic resonance (QM-NMR), time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD), and optical rotatory dispersion (ORD) methods. In bioassay, compound 6 displayed anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells.

Two new compounds from cultures of the basidiomycete Daedaleopsis tricolor

Two new compounds, daedatrin K (1) and 2-hydroxy-1-(5-(hydroxymethyl)furan-2-yl)propan-1-one (2), were isolated from cultures of the basidiomycetes Daedaleopsis tricolor. The new structures were elucidated on the basis of extensive spectroscopic methods. At the same time, two compounds were tested for their cytotoxicities against five human cancer cell lines. [Formula: see text].

Trichothecrotocins D-L, Antifungal Agents from a Potato-Associated Trichothecium crotocinigenum

Seven new merosesquiterpenoids, trichothecrotocins D-J (1-7), two new trichothecene sesquiterpenoids, trichothecrotocins K (12) and L (13), and six known compounds (8-11, 14, and 15), were isolated from a potato-associated fungus, Trichothecium crotocinigenum. Compounds 5 and 6 were racemates which were further separated as pure enantiomers. Structures together with absolute configurations were established by extensive spectroscopic analysis, as well as quantum chemistry calculations on ECD and optical rotations. Compounds 1-4 are rare meroterpenoids featuring a seco-phenyl group, while 1 and 2 possessed a novel 6-6/5 fused ring system. Compounds 1-4, 8, 11, and 12 showed antifungal activity against four plant pathogens with MIC values of 8-128 μg/mL. It is suggested that the meroterpenoids produced by T. crotocinigenum may play an important role in the antifungal property of the fungus, thereby protecting the host plant, i.e., potato.

Lanostane Triterpenoids with PTP1B Inhibitory and Glucose-Uptake Stimulatory Activities from Mushroom Fomitopsis pinicola Collected in North America

A chemical investigation on the fruiting bodies of Fomitopsis pinicola led to the isolation and identification of 28 lanostane triterpenoids including 11 new compounds (1-11) and 17 known analogues (12-28). Their structures were elucidated by extensive one-dimensional NMR, two-dimensional NMR, and MS spectra. All isolates were tested for their anti-inflammatory activity, protein tyrosine phosphatase 1B (PTP1B) inhibitory activity in vitro, and effect on glucose uptake in insulin-resistant HepG2 cells. Compounds 1, 4, 22, 23, and 27 inhibited the nitric oxide released from the LPS-induced RAW 264.7 cell assay with IC₅₀ values in the range of 21.4-27.2 μM. Compounds 18, 22, 23, and 28 showed strong PTP1B inhibitory activity with IC₅₀ values in the range of 20.5-29.9 μM, comparable to that of the positive control of oleanolic acid (15.0 μM). Compounds 18 and 22 were confirmed to be good competitive inhibitors of PTP1B by kinetic analysis. In addition, compounds 18, 22, and 28 were found to stimulate glucose uptake in the insulin-resistant HepG2 cells in the dose from 6.25 to 100 μM. These findings indicated the potential of F. pinicola in the development of functional food or medicine for the prevention and treatment of diabetes.

Chemical constituents and their cytotoxicities from mushroom Tricholoma imbricatum

Two undescribed triterpenes, tricholimbrins A and B, three undescribed steroids, tricholimbrins C‒E, one undescribed 4-chromanone derivative, along with 27 known compounds were isolated from fruiting bodies of the mushroom Tricholoma imbricatum. Tricholimbrins A and B are two polycyclic triterpenoids with a carbon degradation, while tricholimbrin C is a ring-rearranged steroid containing an aromatic moiety that might be derived from an ergosterol. Isocyathisterol, 3β,15α-dihydroxyl-(22E,24R)-ergosta-5,8(14),22-trien-7-one, demethylincisterol A₃, and volemolide showed cytotoxicities to six human cancer cell lines. 3β-Hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7,15-dione and 3β-hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7-one showed preferable cytotoxicities against HL-60 while chaxine C and volemolide showed preferable cytotoxicities against A-549, with IC₅₀ values less than 10 μM.

A critical review on submerged production of mushroom and their bioactive metabolites

Mushrooms are ubiquitous in nature. Even though humankind has been consuming mushrooms for ages, their medicinal and nutraceutical properties are not used to its fullest potential in the present market. Edible mushrooms are not only a cheap and nutritious option to mitigate malnutrition, but they also produce effective biomass. Submerged fermentation (SmF) is not only a cost-effective method to produce biomass along with exquisite bioactive metabolites but it also reduces the chances of contamination and the time of production. Therefore, this study unveils the bioactive metabolites being produced by mushrooms. Moreover, it also showcases the recent advances in the areas of bio-active compounds and their judicious implementations in daily life and pharmaceutical industries. Moreover, there is a distinct lack in utilizing the potential benefits of bioactive compounds from mushroom unless in vivo and in vitro studies are demonstrated.

In Depth Natural Product Discovery from the Basidiomycetes Stereum Species

Natural metabolites from microorganisms play significant roles in the discovery of drugs, both for disease treatments in humans, and applications in agriculture. The Basidiomycetes Stereum genus has been a source of such bioactive compounds. Here we report on the structures and activities of secondary metabolites from Stereum. Their structural types include sesquiterpenoids, polyketides, vibralactones, triterpenoids, sterols, carboxylic acids and saccharides. Most of them showed biological activities including cytotoxic, antibacterial, antifungal, antiviral, radical scavenging activity, autophagy inducing activity, inhibiting pancreatic lipase against malarial parasite, nematocidal and so on. The syntheses of some metabolites have been studied. In this review, 238 secondary metabolites from 10 known species and various unidentified species of Stereum were summarized over the last seven decades.

Cyperane-Type and Related (Nor)Sesquiterpenoids from the Root Bark of Acanthopanax gracilistylus and Their Inhibitory Effects on Nitric Oxide Production

An enantiomeric pair of rare cyperane-type sesquiterpenoids, (+)- and (-)-gracilistones C (1a, 1b), together with a novel norsesquiterpenoid, gracilistone D (2), bearing a bicyclic lactone system were isolated from the root bark of Acanthopanax gracilistylus using LC-MS-IT-TOF analyses. The structures and absolute configurations of 1a, 1b, and 2 were elucidated by 1D and 2D NMR spectroscopy, X-ray diffraction, and ECD spectroscopic methods. Intermediate 1b suggests a possible biosynthesis process involving compound 2. The bioassay results showed that compounds 1a, 1b, and 2 exhibited significant inhibitory effects against lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells, with IC₅₀ values of 7.7 ± 0.6, 6.8 ± 1.5, and 2.6 ± 0.4 μM, respectively. Additional docking analyses provided some perspective of this activity in human inducible nitric oxide synthase.

Pleurocorols A and B: rearranged steroids from the fruiting bodies of Pleurotus cornucopiae

Pleurocorols A and B, unprecedented steroids with an 11(9 → 8)abeo-ergostane and a 5(6 → 7), 11(9 → 7)diabeo-ergostane skeleton, respectively, were isolated from Pleurotus cornucopiae.

Ochracines A-E, chamigrane-related norsesquiterpene derivatives from the basidiomycete Steccherinum ochraceum HFG119

Ochracines A-E, five previously undescribed norsesquiterpenes featured by unusual scaffolds biogenetically related to chamigrane, were isolated from the cultures of Steccherinum ochraceum. Ochracines A (1) and B (2) represent the first examples of norsesquiterpenes with an unprecedented 1,2-6,7-diseco-1,8-cyclochamigrane scaffold. Ochracines C-D (3-5) possess an unusual 1,2-6,7-diseco-chamigrane skeleton. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of ochracine A (1), and the relative configuration of ochracine B (2) were determined by ECD and/or NMR calculations. The biosynthetic pathways for the norsesquiterpenes were proposed. All isolates were evaluated for their cytotoxicity against the five human cancer cell lines HL-60, SMMC-7721, A549, MCF-7, and SW-480.

C30 and C31 Triterpenoids and Triterpene Sugar Esters with Cytotoxic Activities from Edible Mushroom Fomitopsis pinicola (Sw. Ex Fr.) Krast

Fomitopsis pinicola (Sw. Ex Fr.) Krast has been commonly used as a health food source and antitumor agent. To uncover bioactive key composition of F. pinicola, in our study, we investigated the chemical constituents of a methanol extract of F. pinicola and thirty-five lanostane-type tritetpenoids; 13 new compounds (1-13) and twenty-two known analogues (14-35) were isolated. Among them, compounds 1-9 were C30 lanostane triterpenoids and triterpene sugar esters, while compounds 10-13 were C31 triterpenoids and triterpene sugar esters. Their structures and absolute configurations were elucidated by extensive 1D, 2D NMR, MS, and IR spectra. Furthermore, cytotoxic activities of all isolates against five human tumor cell lines (HL-60, A549, SMMC-7721, MCF-7, and SW480) were evaluated. The results showed that compounds 12, 14, 17, 18, 22, and 23 displayed cytotoxic effects against five human tumor cell lines with IC₅₀ values ranging from 3.92-28.51 μM. Meanwhile, compounds 9 and 35 exhibited selected inhibitory activities against HL-60, SMMC-7721, and MCF-7 with IC₅₀ values in the range of 13.57-36.01 μM. Furthermore, the flow cytometry analysis revealed that compounds 17, 22, and 35 induced apoptosis in HL-60 cell lines. Their structure-activity relationships were preliminarily reported. These findings indicate the vital role of triterpenoids and their glycosides in explaining antitumor effects of F. pinicola and provide important evidence for further development and utilization of this fungus.

Cytotoxic ergosterols from cultures of the basidiomycete Psathyrella candolleana

Three newly isolated ergosterols, psathergosterols A-C (1-3), together with two known ones (4 and 5), have been isolated from cultures of the basdiomycete Psathyrella candolleana. Their structures with the absolute configuration were elucidated by means of spectroscopic methods and the single crystal X-ray diffraction. Compounds 2-4 exhibited certain cytotoxicities to five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW480).

Triterpenoids and steroids from the fruiting bodies of Hexagonia tenuis and their cytotoxicity

One new triterpenoid, hexagonin F (1) was characterized from the fruiting bodies of Hexagonia tenuis with the assistance of spectroscopic and spectrometric analytical methods. In addition, two triterpenoids and two steroids were also identified by comparison of their physical and spectroscopic data with those reported. The purified compounds were examined for their cytotoxicity against five tumor cell lines, however, only weak cytotoxicity was demonstrated.

Tricholopardins A and B, Anti-inflammatory Terpenoids from the Fruiting Bodies of Tricholoma pardinum

Two new Tricholoma terpenoids, tricholopardins A and B, were isolated from the fruiting bodies of the basidiomycetes Tricholoma pardinum. Their structures were elucidated by spectroscopic methods, as well as electronic circular dichroism and optical rotatory dispersion calculations. Tricholopardin A potently inhibited nitric oxide production in lipopolysaccharide-induced RAW264.7 macrophages with an IC₅₀ of 0.08 μM. Its anti-inflammatory effects on three inflammatory mediators were also evaluated. A plausible biosynthetic pathway for these products is discussed.

Rearranged ergostane-type natural products: chemistry, biology, and medicinal aspects

Rearranged ergostane-type natural products are structurally intriguing and exhibit biologically relevant properties.

Polyoxygenated meroterpenoids and a bioactive illudalane derivative from a co-culture of Armillaria sp. and Epicoccum sp

Four new meroterpenoids were discovered from a co-culture of Armillaria sp. and the endophytic fungus Epicoccum sp. YUD17002.

Trichothecrotocins A-C, Antiphytopathogenic Agents from Potato Endophytic Fungus Trichothecium crotocinigenum

Two trichothecene sesquiterpenoids, trichothecrotocins A (1) and B (2), and a merosesquiterpenoid racemate, (±)-trichothecrotocin C (3), were obtained from potato endophytic fungus Trichothecium crotocinigenum by bioguided isolation. Their structures were elucidated by extensive spectroscopic methods, electronic circular dichroism calculations, and single-crystal X-ray diffraction. Compounds 1 and 2 are trichothecenes possessing new ring systems. Compound 3 possesses a novel 6/6-5/5/5 fused ring system. Compounds 1-3 showed antiphytopathogenic activities with MIC values of 8-128 μg/mL.

Irpeksins A-E, 1,10- seco-Eburicane-Type Triterpenoids from the Medicinal Fungus Irpex lacteus and Their Anti-NO Activity

Five new triterpenoids, irpeksins A-E (1-5), were isolated from fruiting bodies of the medicinal fungus Irpex lacteus. The structures as well as absolute configurations of the new compounds were established via extensive spectroscopic analysis, computational methods, and Cotton effects. Compounds 1-4 are featured by a scaffold of 1,10- seco- and ring B aromatic eburicane (24-methyllanostane), and compound 5 is characterized by a scaffold of 1,10-9,11- diseco- and ring B aromatic eburicane, which represents unprecedented cleavage patterns in the lanostane family. Compounds 1-5 showed significant inhibitory activity against NO production in LPS-activated RAW 264.7 macrophage cells with IC₅₀ values varying from 2.2 to 19.6 μM.

Survey of natural products reported by Asian research groups in 2017

The new natural products reported in 2017 in peer-reviewed articles in journals with good reputations were reviewed and analyzed. The advances made by Asian research groups in the field of natural products chemistry in 2017 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification.

Secondary Metabolites Isolated fromTricholomaSpecies (Basidiomycota, Tricholomatacee): A Review

The large mushroom genus Tricholoma (Fr.) Staude comprises hundreds of species growing worldwide. Phytochemical studies on the contents of these mushrooms have been increasing steadily in the last decades; this review is the first complete report about the secondary metabolites isolated to date (January 2018) from the fruiting bodies, with the exclusion of most volatile constituents. The structures, presumed biogenesis, and bioactivities of identified compounds, divided in families according to their biogenesis, are critically discussed. A brief chemotaxonomic discussion of the genus Tricholoma is included in the final part of the review.

Heterocyclic Compounds from the Mushroom Albatrellus confluens and Their Inhibitions against Lipopolysaccharides-Induced B Lymphocyte Cell Proliferation

Eight hetereocyclic compounds conflamides B-I with an unprecedented skeleton and their precursor conflamide A were isolated from the mushroom Albatrellus confluens. Their structures and absolute configurations were determined by use of NMR studies, total synthesis, and calculated ECD spectra. Conflamides D and E were found to exhibit potent inhibition against LPS-induced B lymphocyte cell proliferation with IC₅₀ values 1.48 and 5.71 μM, respectively.