Molecular Diversity and Potential Anti-neuroinflammatory Activities of Cyathane Diterpenoids from the Basidiomycete Cyathus africanus

Enantioselective Total Synthesis of (-)-Cyathin B2: A Desymmetric Double-Allylboration Approach

A powerful Pt-catalyzed asymmetric diboration/desymmetric double-allylboration cascade reaction has been developed for the construction of synthetically useful, densely functionalized hydrindanes with five stereocenters, including three quaternary ones, in good yields and excellent enantiomeric excess (ee) values within a single synthetic operation. A unified strategy utilizing this key tandem methodology enabled the concise asymmetric total synthesis of cyathane diterpene (-)-Cyathin B2 in 14 steps from commercially available starting materials, thereby demonstrating its remarkable potential in the synthesis of hydrindane-containing natural products and pharmaceuticals.

Could Mushrooms' Secondary Metabolites Ameliorate Alzheimer Disease? A Computational Flexible Docking Investigation

Herein, we highlight the significance of molecular modeling approaches prior to in vitro and in vivo studies; particularly, in diseases with no recognized treatments such as neurological abnormalities. Alzheimer disease is a neurodegenerative disorder that causes irreversible cognitive decline. Toxicity and ADMET studies were conducted using the Qikprop platform in Maestro software and Discovery Studio 2.0, respectively, to select the promising skeletons from more than 45 reviewed compounds isolated from mushrooms in the last decade. Using rigid and flexible molecular docking approaches such as induced fit docking (IFD) in the binding sites of β-secretase (BACE1) and acetylcholine esterase (ACHE), promising structures were screened through high precision molecular docking compared with standard drugs donepezil and (2E)-2-imino-3-methyl-5,5-diphenylimidazolidin-4-one (OKK) using Maestro and Cresset Flare platforms. Molecular interactions, binding distances, and RMSD values were measured to reveal key interactions at the binding sites of the two neurodegenerative enzymes. Analysis of IFD results revealed consistent bindings of dictyoquinazol A and gensetin I in the pocket of 4ey7 while inonophenol A, ganomycin, and fornicin fit quite well in 4dju demonstrating binding poses very close to native ligands at ACHE and BACE1. Respective key amino acid contacts manifested the least steric problems according to their Gibbs free binding energies, Glide XP scores, RMSD values, and molecular orientation respect to the key amino acids. Molecular dynamics simulations further confirmed our findings and prospected these compounds to show significant in vitro results in their future pharmacological studies.

Genome-wide characterization and metabolite profiling of Cyathus olla: insights into the biosynthesis of medicinal compounds

Cyathus olla, belonging to the genus Cyathus within the order Agaricales, is renowned for its bird's nest-like fruiting bodies and has been utilized in folk medicine. However, its genome remains poorly understood. To investigate genomic diversity within the genus Cyathus and elucidate biosynthetic pathways for medicinal compounds, we generated a high-quality genome assembly of C. olla with fourteen chromosomes. The comparative genome analysis revealed variations in both genomes and specific functional genes within the genus Cyathus. Phylogenomic and gene family variation analyses provided insights into evolutionary divergence, as well as genome expansion and contraction in individual Cyathus species and 36 typical Basidiomycota. Furthermore, analysis of LTR-RT and Ka/Ks revealed apparent whole-genome duplication (WGD) events its genome. Through genome mining and metabolite profiling, we identified the biosynthetic gene cluster (BGC) for cyathane diterpenes from C. olla. Furthermore, we predicted 32 BGCs, containing 41 core genes, involved in other bioactive metabolites. These findings represent a valuable genomic resource that will enhance our understanding of Cyathus species genetic diversity. The genome analysis of C. olla provides insights into the biosynthesis of medicinal compounds and establishes a fundamental basis for future investigations into the genetic basis of chemodiversity in this significant medicinal fungus.

The First Five Mitochondrial Genomes for the Family Nidulariaceae Reveal Novel Gene Rearrangements, Intron Dynamics, and Phylogeny of Agaricales

The family Nidulariaceae, consisting of five genera including Cyathus, is a unique group of mushrooms commonly referred to as bird's nest fungi due to their striking resemblance to bird's nests. These mushrooms are considered medicinal mushrooms in Chinese medicine and have received attention in recent years for their anti-neurodegenerative properties. However, despite the interest in these mushrooms, very little is known about their mitochondrial genomes (mitogenomes). This study is the first comprehensive investigation of the mitogenomes of five Nidulariaceae species with circular genome structures ranging in size from 114,236 bp to 129,263 bp. Comparative analyses based on gene content, gene length, tRNA, and codon usage indicate convergence within the family Nidulariaceae and heterogeneity within the order Agaricales. Phylogenetic analysis based on a combined mitochondrial conserved protein dataset provides a well-supported phylogenetic tree for the Basidiomycetes, which clearly demonstrates the evolutionary relationships between Nidulariaceae and other members of Agaricales. Furthermore, phylogenetic inferences based on four different gene sets reveal the stability and proximity of evolutionary relationships within Agaricales. These results reveal the uniqueness of the family Nidulariaceae and its similarity to other members of Agaricales; provide valuable insights into the origin, evolution, and genetics of Nidulariaceae species; and enrich the fungal mitogenome resource. This study will help to expand the knowledge and understanding of the mitogenomes in mushrooms.

Unveiling the Therapeutic Potentials of Mushroom Bioactive Compounds in Alzheimer's Disease

Alzheimer's disease (AD) stands as a prevailing neurodegenerative condition (NDs), leading to the gradual deterioration of brain cells and subsequent declines in memory, thinking, behavior, and emotion. Despite the intensive research efforts and advances, an effective curative treatment for the disease has not yet been found. Mushrooms, esteemed globally for their exquisite flavors and abundant nutritional benefits, also hold a wealth of health-promoting compounds that contribute to improving AD health. These compounds encompass polysaccharides, proteins, lipids, terpenoids, phenols, and various other bioactive substances. Particularly noteworthy are the potent neuroprotective small molecules found in mushrooms, such as ergothioneine, erinacine, flavonoids, alkaloids, ergosterol, and melanin, which warrant dedicated scrutiny for their therapeutic potential in combating AD. This review summarizes such positive effects of mushroom bioactive compounds on AD, with a hope to contribute to the development of functional foods as an early dietary intervention for this neurodegenerative disease.

Tracing the Path between Mushrooms and Alzheimer's Disease-A Literature Review

Alzheimer's disease (AD) is well-known among neurodegenerative diseases for the decline of cognitive functions, making overall daily tasks difficult or impossible. The disease prevails as the most common form of dementia and remains without a well-defined etiology. Being considered a disease of multifactorial origin, current targeted treatments have only managed to reduce or control symptoms, and to date, only two drugs are close to being able to halt its progression. For decades, natural compounds produced by living organisms have been at the forefront of research for new therapies. Mushrooms, which are well-known for their nutritional and medicinal properties, have also been studied for their potential use in the treatment of AD. Natural products derived from mushrooms have shown to be beneficial in several AD-related mechanisms, including the inhibition of acetylcholinesterase (AChE) and β-secretase (BACE 1); the prevention of amyloid beta (Aβ) aggregation and neurotoxicity; and the prevention of Tau expression and aggregation, as well as antioxidant and anti-inflammatory potential. Several studies in the literature relate mushrooms to neurodegenerative diseases. However, to the best of our knowledge, there is no publication that summarizes only AD data. In this context, this review aims to link the therapeutic potential of mushrooms to AD by compiling the anti-AD potential of different mushroom extracts or isolated compounds, targeting known AD-related mechanisms.

Secondary Metabolites of Bird's Nest Fungi: Chemical Structures and Biological Activities

Bird's nest fungi, a general term for species in the family Nidulariaceae, are named for their fruiting bodies that resemble bird's nests. Two of their members, Cyathus stercoreus (Schw.) de Toni. and Cyathus striatus Will. ex Pers., are known as medicinal fungi in Chinese medicine. Bird's nest fungi produce a variety of secondary metabolites that provide natural materials for screening and developing medicinal compounds. This review presents a systematic summary of the literature on the secondary metabolites of bird's nest fungi up to January 2023, including 185 compounds, mainly cyathane diterpenoids, with prominently characterized antimicrobial and antineurodegenerative activities. Our work aims to advance our understanding of bird's nest fungi and support studies on their natural product chemistry, pharmacology, and biosynthesis of secondary metabolites.

Onychiol B attenuates lipopolysaccharide-induced inflammation via MAPK/NF-κB pathways and acute lung injury in vivo

Acute lung injury (ALI) is a devastating respiratory disorder characterized by rapid alveolar injury, uncontrolled inflammatory response, etc. Onychiol B is a cyathane diterpene originally isolated from fern plants. In this study, onychiol B can inhibit the production and secretion of pro-inflammatory cytokines such as NO, iNOS, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells by restraining the NF-κB and the p38 MAPK pathway. In addition, it prevents the production of ROS and reduces the loss of mitochondrial membrane potential in LPS-stimulated RAW264.7 cells. Furthermore, in the acute lung injury mouse model induced by LPS injected into the trachea, onychiol B alleviates pulmonary edema, reverses inflammatory mediator TNF-α, IL-6, and IL-β secretion in lung. In general, our data show that significant anti-ALI effects of onychiol B would render it a potential candidate for the treatment of inflammatory diseases.

Mushroom Natural Products in Neurodegenerative Disease Drug Discovery

The variety of drugs available to treat neurodegenerative diseases is limited. Most of these drug's efficacy is restricted by individual genetics and disease stages and usually do not prevent neurodegeneration acting long after irreversible damage has already occurred. Thus, drugs targeting the molecular mechanisms underlying subsequent neurodegeneration have the potential to negate symptom manifestation and subsequent neurodegeneration. Neuroinflammation is a common feature of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis, and is associated with the activation of the NLRP3 inflammasome, which in turn leads to neurodegeneration. Inflammasome activation and oligomerisation is suggested to be a major driver of disease progression occurring in microglia. With several natural products and natural product derivatives currently in clinical trials, mushrooms have been highlighted as a rich and largely untapped source of biologically active compounds in both in vitro and in vivo neurodegenerative disease models, partially supported by successful clinical trial evaluations. Additionally, novel high-throughput methods for the screening of natural product compound libraries are being developed to help accelerate the neurodegenerative disease drug discovery process, targeting neuroinflammation. However, the breadth of research relating to mushroom natural product high-throughput screening is limited, providing an exciting opportunity for further detailed investigations.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated β-D-fucopyranosyl and β-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC₅₀ values ranging from 1.58 to 28.74 μM. Structure-activity relationships of the isolated compounds are discussed.

Structurally Diverse Sesquiterpenoid Glycoside Esters from Pittosporum qinlingense with Anti-neuroinflammatory Activity

Thirteen new sesquiterpenoid glycoside esters, including 11 aromadendrane-type compounds, pitqinlingosides A-K (1-11), one cadinane-type compound, pitqinlingoside L (12), and one eudesmane-type compound, pitqinlingoside M (13), together with seven known analogues (14-20) were isolated from the twigs, fruits, and leaves of Pittosporum qinlingense. Structures were elucidated by analysis of spectroscopic data, gas chromatography mass spectrometry (GC-MS), and chemical methods. The absolute configuration was confirmed by single-crystal X-ray crystallography analysis or electronic circular dichroism spectra. Unusual glycoside esters are characterized by the presence of polyacylated β-d-fucopyranosyl, β-d-glucopyranosyl, and β-d-xylopyranosyl units. Pitqinlingosides A (1), B (2), D (4), and F (6), pittosporanoside A₁ acetate (14), and pittosporanoside A₁ (16) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC₅₀ values ranging from 0.95 to 24.12 μM. Structure-activity relationships of the isolated compounds are discussed.

Thirteen cyathane diterpenoids with acetylcholinesterase inhibitory effects from the fungus Cyathus africanus

Eight undescribed cyathane diterpenoids, representative specialised metabolites of the genus Cyathus, named cyathins Q-X, along with five known congeners, were isolated from the liquid fermentation of Cyathus africanus. Their structures and absolute configurations were elucidated by integrating NMR spectroscopic analyses, electronic circular dichroism (ECD) calculations, and X-ray diffraction. Reasonable correction to the C-12 configuration of cyathin I was corroborated by the crystal data. The structural identification in this research expanded the number of candidates to allow for more bioactivity-screening options. Among them, (12S)-11α,14α-epoxy-13α,14β,15-trihydroxycyath-3-ene displayed significant acetylcholinesterase (AChE) inhibitory effect with an IC₅₀ value of 4.60 ± 0.85 μM. Molecular docking studies were also performed to unravel the underlying modes of interactions with the active sites of AChE for active compounds.

The Phosphinamide-Based Catalysts: Discovery, Methodology Development, and Applications in Natural Product Synthesis

In the total synthesis of natural products, synthetic efficiency has been an important driver for designing and developing new synthetic strategies and methodologies. To this end, the step, atom, and time economy and the overall yield are major factors to be considered. On the other hand, developing unified routes that can be used for synthesizing multiple molecules, specifically skeletally different classes of molecules, are also important aspects with which to be concerned. In the efforts toward efficient and flexible synthesis of structurally unique terpenoid and indole alkaloid natural products, we have designed and developed several phosphinamide-based new catalysts and reaction methodologies that have been compellingly demonstrated to be widely useful as strategic protocols for the diverse synthesis of various complex terpenoids and indole alkaloids. The important progress of these results will be summarized in this Account.In the first part, we present the stories of successful design and establishment of a novel method for the synthesis of P-stereogenic phosphinamides (P-SPhos) via a Pd-catalyzed C-H desymmetric enantioselective arylation, as well as the flexible derivatization of the P-stereogenic phosphinamides into various types of skeletally unique tricyclic and N,P-bidentate P-stereogenic compounds. Subsequently, the discovery of P-stereogenic phosphinamides as chiral organocatalysts for the desymmetric enantioselective reduction of cyclic 1,3-diketones and of phosphinamide-based cyclopalladium complex (C-Pd) as precatalysts for highly efficient Suzuki-Miyaura cross-coupling reaction of sterically congested nonactivated enolates is introduced. The notable features of the P-stereogenic phosphinamide-catalyzed desymmetric enantioselective reduction are highlighted by the broad substrate compatibility and excellent stereoselectivity, as well as most significantly, the good recoverability and reusability of catalysts. With regard to the sterically congested nonactivated enolates, such substrates are challenging for Suzuki cross-coupling reactions. We demonstrate that the phosphinamide-based cyclopalladium is a type of highly active precatalyst that allows the reaction to proceed under mild conditions and to be easily scaled up. Following the methodology development, the practical applications of these methods serving as strategic transformations are highlighted by the unified synthesis of four cyathane-type and two hamigeran-type terpenoids.In the second part, we describe the development of a robust method for oxidative Heck cross-coupling of indolyl amides by using the phosphinamide-based cyclopalladium as catalyst or phosphinamide as coligand. The method provides a general and straightforward method for diverse synthesis of indolyl δ-lactam derivatives, which present as a common core in a variety of Aspidosperma-derived indole alkaloids. The successful demonstration of this protocol for a concise and divergent synthesis of leuconodine-type indole alkaloids is also presented. We believe the results presented in this Account would have significant implications beyond our results and would find further applications in the field of synthetic methodology and natural product synthesis.

Ganorbifates A and B from Ganoderma orbiforme, determined by DFT calculations of NMR data and ECD spectra

Ganorbifate A featuring an unprecedented 6/6/6/5/5 pentacyclic system, and ganorbifate B with an unusual 6/4/6/5/8/5 ring system were isolated from the fruiting body of Ganoderma orbiforme. Their structures were established using extensive spectroscopic analysis, including DFT calculations of NMR data and ECD spectra.

Anti-neuroinflammatory polyoxygenated lanostanoids from Chaga mushroom Inonotus obliquus

Chaga mushroom, Inonotus obliquus, was used as food and nutrient food and traditional herbs in Russia, China and Japan, with anti-inflammatory and anticancer activities. Chemical investigations of the fruiting bodies of Chaga were carried to uncover the bioactive metabolites. As a result, seven undescribed lanostane-type triterpenoids, namely inonotusols H-N, were isolated, and all lanostanoids remarkably inhibited NO production in lipopolysaccharide-stimulated BV-2 microglial cells. Of these, inonotusols I and L presented the most potent inhibitory effects on inducible nitric oxide synthase (iNOS) and NO production without any significant cytotoxicity. Molecular docking studies confirmed the capacity of inonotusols I and L to interact with iNOS protein. Structure-activity relationships were also discussed. These results indicated that the potential anti-inflammatory effects of inonotusols I and L in microglial BV-2 cells may be imparted through suppression of iNOS. These results may support the use of I. obliquus for food and medicinal application.

Biological Evaluation of Aegle marmelos Fruit Extract and Isolated Aegeline in Alleviating PainDepression Dyad: In Silico Analysis of Aegeline on MAO-A and iNOS

Pain and depression have been assessed to co-occur in up to 80% of patients, and this comorbidity is more debilitating and pricier for the patients as compared to either of these disorders alone. Aegle marmelos is a well-known medicinal plant with a broad spectrum of pharmacological activities. Aegeline is a relatively unexplored molecule present in Aegle marmelos. Therefore, the current investigation aims to explore the potential of Aegle marmelos fruit extract (AMFE) and isolated aegeline against the reserpine-induced pain-depression dyad. In the current investigation, aegeline was isolated from AMFE, followed by spectroscopic characterization, i.e., using NMR and mass analyses. AMFE (200 mg kg^-1 p.o) and aegeline (10 mg kg^-1 p.o.) were administered to reserpinized (0.5 mg kg^-1 s.c.) mice, and clorgyline (3 mg kg^-1 i.p.) was taken as the standard drug. AMFE and aegeline significantly alleviated the reserpine-induced reduction in a pain threshold and an increase in immobility as observed in behavioral tests of pain and depression, respectively. In silico molecular docking studies of aegeline showed a good binding interaction at the active sites of MAO-A and iNOS. The in vivo analysis showed that AMFE and aegeline treatment significantly decreased the monoamine oxidase-A (MAO-A) activity, serum interleukin-6 (IL-6) level, and lipid peroxidation, along with an increase in the reduced glutathione level in comparison to the reserpine-treated group. Immunofluorescence studies also showed that AMFE and aegeline abrogated the reserpine-induced increase in iNOS expression. Conclusively, the results delineate that AMFE and aegeline might exert a protective effect via downregulating the MAO-A hyperactivity, IL-6 level, oxidative and nitrosative stress.

Impact of STEMI Diagnosis and Catheterization Laboratory Activation Systems on Sex- and Age-Based Differences in Treatment Delay

Background

Women and the elderly with ST-elevation myocardial infarction (STEMI) experience longer treatment delays despite prehospital STEMI diagnosis and catheterization laboratory activation systems. It is not known what role specific STEMI referral systems might play in mediating this gap in care. We therefore examined sex- and age-based differences in STEMI treatment delay (TD) in different STEMI activation systems.

Methods

This observational comparative effectiveness study comprised 3 retrospective STEMI cohorts: a traditional hospital-based activation cohort (Cohort 1), an automated “physician-blind” prehospital activation cohort (Cohort 2), and a prehospital activation with real-time physician oversight cohort (Cohort 3). Outcomes of interest included sex and age group (< or ≥ 75 years) differences in suboptimal (> 90 minutes) first medical contact-to-device time (FMC-to-device) within each cohort, as well as independent predictors of suboptimal FMC-to-device and in-hospital mortality across cohorts.

Results

Five hundred-sixty STEMI activations were analyzed. In Cohort 1 (n = 179), women and those ≥ 75 were more likely to experience suboptimal FMC-to-device times (78.7% vs 36.4%, P = 0.02 and 85.0% vs 58.3%, < 0.01, respectively). Similar findings were observed in Cohort 3 (n = 109) (53.5% vs 32.9%, 56.5% vs 33.3%, respectively; P = 0.05, for both). In Cohort 2 (n = 272), however, there was no significant age-based difference (30.4% vs 21.7%, P = 0.18), and the gap was numerically lower but still significant for women (32.1% vs 20.1%, P = 0.04). When examining prehospital activation cohorts only, female sex (P = 0.03), off-hours presentation (P < 0.01), and physician oversight (P < 0.01) were independent predictors of longer FMC-to-device times. Age ≥ 75 (P < 0.01), Killip class (P < 0.01), and female sex (P = 0.04) were independently associated with in-hospital mortality.

Conclusions

Automated “physician-blind” STEMI activation was associated with a reduced TD gap in women and the elderly, suggesting possible systemic bias. Appropriately powered confirmatory studies are required, but incorporating automated diagnosis and catheterization laboratory activation may be a solution to treatment gaps in STEMI care.

Synthesis and Biological Evaluation of Diversified Hamigeran B Analogs as Neuroinflammatory Inhibitors and Neurite Outgrowth Stimulators

We describe the efficient synthesis of a series of new simplified hamigeran B and 1-hydroxy-9-epi-hamigeran B norditerpenoid analogs (23 new members in all), structurally related to cyathane diterpenoid scaffold, and their anti-neuroinflammatory and neurite outgrowth-stimulating (neurotrophic) activity. Compounds 9a, 9h, 9o, and 9q exhibited moderate nerve growth factor (NGF)-mediated neurite-outgrowth promoting effects in PC-12 cells at the concentration of 20 μm. Compounds 9b, 9c, 9o, 9q, and 9t showed significant nitric oxide (NO) production inhibition in lipopolysaccharide (LPS)-activated BV-2 microglial cells, of which 9c and 9q were the most potent inhibitors, with IC₅₀ values of 5.85 and 6.31 μm, respectively. Two derivatives 9q and 9o as bifunctional agents displayed good activities as NO production inhibitors and neurite outgrowth-inducers. Cytotoxicity experiments, H₂O₂-induced oxidative injury assay, and ELISA reaction speculated that compounds may inhibit the TNF-α pathway to achieve anti-inflammatory effects on nerve cells. Moreover, molecular docking studies provided a better understanding of the key structural features affecting the anti-neuroinflammatory activity and displayed significant binding interactions of some derivatives (like 9c, 9q) with the active site of iNOS protein. The structure-activity relationships (SARs) were also discussed. These results demonstrated that this structural class compounds offered an opportunity for the development of a new class of NO inhibitors and NGF-like promotors.

Erinacine A and related cyathane diterpenoids: Molecular diversity and mechanisms underlying their neuroprotection and anticancer activities

The presence of a fused 5/6/7 tricyclic core characterizes the group of cyathane diterpene natural products, that include more than 170 compounds, isolated from fungi such as Cyathus africanus and Hericium erinaceus. These compounds have a common biosynthetic precursor (cyatha-3,12-diene) and can be produced bio- or hemi-synthetically, or via total syntheses. Cyathane diterpenes display a range of pharmacological properties, including anti-inflammatory (possibly through binding to the iNOS protein) and neuroprotective effects. Many cyathanes like cyahookerin C, cyathin Q and cyafranines B and G can stimulate neurite outgrowth in cells, whereas conversely a few molecules (such as scabronine M) inhibit NGF-stimulated neurite outgrowth. The main anticancer cyathanes are erinacine A and cyathins Q and R, with a capacity to trigger cancer cell death dependent on the production of reactive oxygen species (ROS). These compounds, active both in vitro and in vivo, activate different signaling pathways in tumor cells to induce apoptosis (and autophagy) and to upregulate the expression of several proteins implicated in the organization and functioning of the actin cytoskeleton. An analysis of the functional analogy between erinacine A and other natural products known to interfere with the actin network in a ROS-dependent manner (notably cucurbitacin B) further supports the idea that erinacine A functions as a perturbator of the cytoskeleton organization. Collectively, we provide an overview of the molecular diversity of cyathane diterpenes and the main mechanisms of action of the lead compounds, with the objective to encourage further research with these fungal products. The anticancer potential of erinacine A deserves further attention but it will be necessary to better characterize the implicated targets and signaling pathways.

A New Epi-neoverrucosane-type Diterpenoid from the Liverwort Pleurozia subinflata in Borneo

New bioactive 13-epi-neoverrucosane diterpenoid, 5β-acetoxy-13-epi-neoverrucosanic acid (1) along with three known secondary metabolites, 13-epi-neoverrucosan-5β-ol (2), chelodane (3) and (E)-β-farnesene (4) were isolated from the MeOH extract of east Malaysia's liverwort Pleurozia subinflata. The chemical structure of new compound was elucidated by the analyses of its spectroscopic data (FTIR, NMR and HR-ESI-MS). These epi-neoverrucosane-type compounds seem to be notable chemosystematic markers for P. subinflata in Borneo. Compound 3 was widespread in marine sponges however this is the first record for 3 to be found in liverwort. These metabolites were tested for their antifungal potentials against selected fungi from the marine environment. Compound 1 exhibited effective antifungal activity against Lagenidium thermophilum.

Cyathane Diterpenes from Cultures of the Bird's Nest Fungus Cyathus hookeri and Their Neurotrophic and Anti-neuroinflammatory Activities

Six new cyathane diterpenoids, cyahookerins A-F (1-6), as well as nine known analogues (7-15), were isolated from the liquid culture of the basidiomycete Cyathus hookeri. Their structures were elucidated on the basis of extensive spectroscopic analyses (1D and 2D NMR, HRESIMS, and ECD), and the absolute configurations of compounds 1 and 4 were determined by single-crystal X-ray crystallography. Compounds 1 and 2 represent the first unusual cyathane acetals featuring a dioxolane ring. Compounds 1-6 displayed differential nerve growth factor-induced neurite outgrowth-promoting activity in PC-12 cells at concentrations of 10 μM. In addition, cyahookerin B (2), cyathin E (9), cyathin B₂ (12), and cyathin Q (13) showed significant nitric oxide production inhibition in Lipopolysaccharide (LPS)-activated BV-2 microglial cells with IC₅₀ values of 12.0, 6.9, 10.9, and 9.1 μM, respectively. Similar binding modes of the four compounds were indicated by molecular-docking studies, and structure-activity relationships are discussed.

Ansamycins with Antiproliferative and Antineuroinflammatory Activity from Moss-Soil-Derived Streptomyces cacaoi subsp. asoensis H2S5

Three new 21-membered macrocyclic benzenoid ansamycins, trienomycins J-L (1-3), together with seven known analogues, trienomycins A-G (4-10), were isolated from liquid culture of the moss soil-derived actinomycete Streptomyces cacaoi subsp. asoensis H2S5. The structures of the new compounds were elucidated by extensive NMR spectroscopic analysis and HRESIMS data. The absolute configurations of trienomycins were established by Marfey's method. Antiproliferative assays showed that compound 1 had the greatest activity against HepG2 cells, with an IC₅₀ value of 0.1 μM. The induction of apoptosis of HepG2 cells by 1 was investigated by flow cytometry and evaluation of nuclear morphology. In addition, all of the compounds inhibited nitric oxide production with IC₅₀ values of 0.02 to 8.3 μM, and compounds 1, 4, and 7 were the most potent inhibitors. These findings will facilitate the development of new antineuroinflammatory agents.

Sarcodonin G Derivatives Exhibit Distinctive Effects on Neurite Outgrowth by Modulating NGF Signaling in PC12 Cells

Sarcodonin G, one of the cyathane diterpenoids isolated from the mushroom Sarcodon scabrosus, possesses pronounced neurotrophic activity but ambiguous mechanical understanding. In this work, sarcodonin G was chosen as a lead compound to prepare a series of 19- O-benzoyl derivatives by semisynthesis and their neuritogenic activities were evaluated. 6 and 15 (10 μM) were investigated with opposite effects in PC12 cells. 6 exhibited a superior activity to sarcodonin G by promoting NGF-induced neurite outgrowth, while 15 showed an inhibitory effect. Supportingly, 6 and 15 (20 μM) significantly induced and suppressed neurite extension in primary cultured rat cortical neurons, respectively. In mechanism, the two derivatives were revealed to influence NGF-induced neurite outgrowth in PC12 cells through the regulation of PKC-dependent and -independent ERK/CREB signaling as well as the upstream TrkA receptor phosphorylation. Furthermore, a possible pattern of interaction among NGF, 6/15 and TrkA was presented using molecular simulations. It revealed that 6/15 may contribute to the stabilization of the NGF-TrkAd5 complex by establishing several hydrophobic and hydrogen-bond interactions with NGF and TrkA, respectively. Taken together, 6 and 15 modulate PKC-dependent and -independent ERK/CREB signaling pathways possibly by influencing the binding affinity of NGF to the receptor TrkA, and finally regulate neurite outgrowth in PC12 cells.

Polyoxygenated cyathane diterpenoids from the mushroom Cyathus africanus, and their neurotrophic and anti-neuroinflammatory activities

In a previous study, we reported ten new polyoxygenated cyathane diterpenoids, neocyathins A-J, and their anti-neuroinflammatory effects from the liquid culture of the medicinal Basidiomycete Cyathus africanus. In the present study, eight new highly polyoxygenated cyathane diterpenoids, named neocyathins K-R (1-8), were isolated from the solid culture of C. africanus cultivated on cooked rice, together with three known congeners (9-11). The structures and the absolute configurations of the new compounds were elucidated through comprehensive NMR and HRESIMS spectroscopic data, electronic circular dichroism (ECD) data, and chemical conversion. Compounds 1 and 2 represent the first reported naturally occurring compounds with 4,9-seco-cyathane carbon skeleton incorporating an unprecedented medium-sized 9/7 fused ring system, while the 3,4-seco-cyathane derivative (3) was isolated from Cyathus species for the first time. All compounds were evaluated for their neurotrophic and anti-neuroinflammatory activity. All the isolates at 1-25 μM displayed differential nerve growth factor (NGF)-induced neurite outgrowth-promoting activity in PC-12 cells, while one of the compounds, allocyathin B₂ (11), inhibited NO production in lipopolysaccharide (LPS)-stimulated microglia BV-2 cells. In addition, molecular docking studies showed that compound 11 generated interactions with the inducible nitric oxide synthase (iNOS) protein.