Xylarinaps A-E, five pairs of naphthalenone derivatives with neuroprotective activities from Xylaria nigripes

Phlecarinatones H-N: Abietane-type diterpenoids from Phlegmariurus carinatus with proliferative inhibitory effect on U251 glioblastoma cells

Thirteen abietane-type diterpenoids, including seven previously undescribed compounds and six known analogs, were isolated from the root and aerial parts of Phlegmariurus carinatus. Their structures were elucidated by comprehensive spectroscopic data analysis (UV, IR, NMR, and HRESIMS) and quantum chemical calculations (calculated ECD or 13C NMR). Notably, these compounds exhibited high structural diversity. Compounds 1-8 possessed six distinct fused ring systems. Phlecarinatones I (2) and J (3) were identified as rare 6,7-seco-abietane diterpenoids featuring a five-membered lactone ring B. Compounds (1-12) were evaluated for their anti-proliferative activities in the U251 cell line. In particular, phlecarinatone I (2) exhibited potential inhibitory effects on U251 cell proliferation, with an IC50 value of 13.88 ± 1.82 μM. To elucidate the underlying molecular mechanism, p53 signal pathway was enriched from our RNA-seq data. Further investigations using western blot and immunofluorescence assays confirmed that p53 expression was up-regulated in a concentration-independent manner. Additionally, molecular docking studies suggested 2 likely binds to the MDM2-p53 binding region. Finally, an shRNA-mediated MDM2 knockdown experiment provided definitive evidence that 2 acts as a potent inhibitor of glioma proliferation, operating via the modulation of the MDM2-p53 pathway. These findings suggest that 2 might be a valuable of lead compound with anti-proliferative activity.

Five brasilane-type sesquiterpenoids with neuroprotective activities from Xylaria nigripes

Five brasilane-type sesquiterpenoids, including four previously undescribed compounds named xylaribrasilaids A-D, along with a known analogue, were isolated from the ethyl acetate extracts of solid fermentation from Xylaria nigripes. X. nigripes, a traditional Chinese medicinal fungus utilized for treating various ailments such as insomnia, trauma, and depression, has garnered attention due to its pharmacological potential. Their structures and absolute configurations were elucidated through comprehensive spectroscopic analysis, including NMR, HRESIMS, and experimental ECD data. In vitro bioassays were conducted to assess the neuroprotective activities of these compounds against glutamate-induced damage in PC12 cells. Remarkably, all isolated compounds demonstrated significant enhancements in cell viability while concurrently inhibiting apoptosis. Moreover, they effectively attenuated oxidative stress markers, as evidenced by increased activities of superoxide dismutase and glutathione. Furthermore, these compounds displayed the capacity to mitigate intracellular reactive oxygen species accumulation, highlighting their potential in combating oxidative stress-related neurodegenerative disorders.

A pair of new chromone enantiomers from Xylaria nigripes

A pair of new chromone derivative enantiomers, (+)-xylarichromone A (1a) and (-)-xylarichromone A (1b), were isolated from the solid fermentation of Xylaria nigripes. The planar structure of 1 was determined by extensive NMR spectroscopic data, and its absolute configuration was assigned by comparison the ECD spectra with the known chromone derivatives. Compound 1 was the first chromone derivative reported from this medicinal fungus. The neuroprotective effects of 1 against oxygen and glucose deprivation (OGD) induced pheochromocytoma-12 cells (PC12) injury was investigated.

Lycopodium Alkaloids from Phlegmariurus carinatus with Cytotoxic and Neuroprotective Effects

One new fawcettimine-type alkaloid, phlecarinadine A (1), and twelve known ones (2-13) were isolated from the whole plant of Phlegmariurus carinatus. Their chemical structures were unambiguously established by extensive spectroscopic analyses, including nuclear magnetic resonance (NMR) spectroscopic and high resolution electrospray ionization mass spectrometry (HR-ESI-MS). The absolute configuration of 1 was elucidated by the electronic circular dichroism (ECD) technique. These compounds were tested for their cytotoxic and neuroprotective activities. None of these compounds revealed cytotoxic activity against five tumor cells. Phlegmariurine B (2) exhibited potential neuroprotective effects against hemin-induced HT22 cell damage, with a 17.76 % increase in cell survival at 10 μM. In further study, 2 can ameliorate hemin-induced neuronal cell death via an anti-apoptotic pathway. These findings suggest that 2 might be a valuable lead compound with neuroprotective activity.

Neuroprotective methylsuccinic acid and enoic acid derivatives from the fungus Xylaria longipes

Three undescribed methylsuccinic acid derivatives, xylaril acids A-C, and two undescribed enoic acid derivatives, xylaril acids D-E, were isolated from the fungus Xylaria longipes. The structures of the undescribed compounds were deduced by spectroscopic means, including HRESIMS and 1D/2D NMR spectroscopy, as well as ECD calculations. The absolute configuration of xylaril acids A was further determined by single-crystal X-ray diffraction experiments. All the isolated compounds displayed neuroprotective activities against oxygen-glucose deprivation/reperfusion injury in PC12 cells by enhancing cell viability and inhibiting cell apoptosis.

Two New Compounds from the Fungus Xylaria nigripes

In the process of discovering more neural-system-related bioactive compounds from Xylaria nigripes, xylariamino acid A (1), a new amino acid derivative, and a new isovaleric acid phenethyl ester (2) were isolated and identified. Their structures and absolute configurations were determined by analyses of IR, HRESIMS, NMR spectroscopic data, and gauge-independent atomic orbital (GIAO) NMR calculation, as well as electronic circular dichroism (ECD) calculation. The isolated compounds were evaluated for their neuroprotective effects against damage to PC12 cells by oxygen and glucose deprivation (OGD). Compounds 1 and 2 can increase the viability of OGD-induced PC12 cells at all tested concentrations. Moreover, compound 2 (1 μmol L^-1) can significantly reduce the percentage of apoptotic cells.

Fungal Naphthalenones; Promising Metabolites for Drug Discovery: Structures, Biosynthesis, Sources, and Pharmacological Potential

Fungi are well-known for their abundant supply of metabolites with unrivaled structure and promising bioactivities. Naphthalenones are among these fungal metabolites, that are biosynthesized through the 1,8-dihydroxy-naphthalene polyketide pathway. They revealed a wide spectrum of bioactivities, including phytotoxic, neuro-protective, cytotoxic, antiviral, nematocidal, antimycobacterial, antimalarial, antimicrobial, and anti-inflammatory. The current review emphasizes the reported naphthalenone derivatives produced by various fungal species, including their sources, structures, biosynthesis, and bioactivities in the period from 1972 to 2021. Overall, more than 167 references with 159 metabolites are listed.

An important link between the gut microbiota and the circadian rhythm: imply for treatments of circadian rhythm sleep disorder

Currently, gut microbiota living in the gastrointestinal tract, plays an important role in regulating host's sleep and circadian rhythms. As a tool, gut microbiota has great potential for treating circadian disturbance and circadian insomnia. However, the relationship between gut microbiota and circadian rhythms is still unclear, and the mechanism of action has still been the focus of microbiome research. Therefore, this article summarizes the current evidences associating gut microbiota with factors that impact host circadian rhythms neurology sleep disorder. Moreover, we discuss the changes to these systems in sleep disorder and the potential mechanism of intestinal microbiota in regulating circadian rhythms neurology sleep disorder via microbial metabolites. Meanwhile, based on the role of intestinal flora, it is provided a novel insight into circadian related insomnia and will be benefit the dietary treatment of circadian disturbance and the circadian related insomnia.

Xyloketal B: A marine compound with medicinal potential

In recent decades, technological advantages have allowed scientists to isolate medicinal compounds from marine organisms that exhibit unique structure and bioactivity. The mangrove fungus Xylaria sp. from the South China Sea is rich in metabolites and produces a potent therapeutic compound, xyloketal B. Since its isolation in 2001, xyloketal B has been extensively studied in a wide variety of cell types and in vitro and in vivo disease models. Xyloketal B and its derivatives exhibit cytoprotective effects in cardiovascular and neurodegenerative diseases by reducing oxidative stress, regulating the apoptosis pathway, maintaining ionic balance, mitigating inflammatory responses, and preventing protein aggregation. Xyloketal B has also shown to alleviate lipid accumulation in a non-alcoholic fatty liver disease model. Moreover, xyloketal B treatment induces glioblastoma cell death. This review summarizes our current understanding of xyloketal B in various disease models.