Two new sesquiterpenes from cultures of the higher fungus Pholiota nameko

Analysis of microbial community evolution, autolysis phenomena, and energy metabolism pathways in Pholiota nameko endophytes

Introduction

Pholiota nameko is a widely consumed edible fungus. This study focuses on two crucial developmental stages of Pholiota nameko, namely, mycelium and ascospores. The objectives of this research were to investigate changes in microbial diversity and community structure during the growth of Pholiota nameko and to analyze the adaptability of the dominant strains to their respective habitats through metabolic.

Methods

Specifically, we conducted second-generation sequencing of the 16S rRNA gene (Illumina) on samples obtained from these stages. In addition, we isolated and characterized endophytes present in Pholiota nameko, focusing on examining the impact of dominant endophyte genera on autolysis. We also conducted a metabolic pathway analysis.

Results and discussion

The results unveiled 578,414 valid sequences of Pholiota nameko endophytic fungi. At the phylum level, the dominant taxa were Basidiomycota, Ascomycota, Zoopagomycota, and Mucoromycota. At the genus level, the dominant taxa observed were Pholiota, Inocybe, Fusarium, and Hortiboletus. For endophytic bacteria, we obtained 458,475 valid sequences. The dominant phyla were Proteobacteria, TM6, Firmicutes, and Bacteroidetes, while the dominant genera were Edaphobacter, Xanthomonas, Burkholderia, and Pseudomonas. Moreover, we identified the isolated strains in Pholiota nameko using 16S rDNA, and most of them were found to belong to the genus Pseudomonas, with Pseudomonas putida being the most prevalent strain. The findings revealed that the Pseudomonas putida strain has the ability to slow down the breakdown of soluble proteins and partially suppress the metabolic processes that generate superoxide anion radicals in Pholiota nameko, thereby reducing autolysis. Additionally, our results demonstrated that molybdenum enzyme-mediated anaerobic oxidative phosphorylation reactions were the primary energy metabolism pathway in the Pseudomonas putida strain. This suggests that the molybdenum cofactor synthesis pathway might be the main mechanism through which Pholiota nameko adapts to its complex and diverse habitats.

A new illudane sesquiterpene from the edible fungus Pholiota nameko

Fungi have different genetic expression abilities and biosynthetic pathways under different cultivation conditions, which can produce various secondary metabolites. The "one strain many compounds" strategy is used to activate silent biosynthetic genes of fungi to produce various compounds, which is an effective method. In order to discover various new compounds in the edible fungus Pholiota nameko, a fermentation strategy involving precursor feeding and enzyme inhibitor addition has been employed. A new illudane sesquiterpene (1), along with one known indole diterpenoid alkaloid, cladosporine A (2) were isolated from the extracts of liquid culture of P. nameko. The new compound was identified by combination of 1D and 2D NMR, MS, optical rotation, and ECD calculations. We conducted experiments on the cytotoxicity of all isolated compounds on three cancer cell lines, but we did not observe any significant cytotoxicity (IC50 > 40 μM).

Research Progress on Sesquiterpene Compounds from Artabotrys Plants of Annonaceae

Artabotrys, a pivotal genus within the Annonaceae family, is renowned for its extensive biological significance and medicinal potential. The genus's sesquiterpene compounds have attracted considerable interest from the scientific community due to their structural complexity and diverse biological activities. These compounds exhibit a range of biological activities, including antimalarial, antibacterial, anti-inflammatory analgesic, and anti-tumor properties, positioning them as promising candidates for medical applications. This review aims to summarize the current knowledge on the variety, species, and structural characteristics of sesquiterpene compounds isolated from Artabotrys plants. Furthermore, it delves into their pharmacological activities and underlying mechanisms, offering a comprehensive foundation for future research.

Anticancer Activities of Mushrooms: A Neglected Source for Drug Discovery

Approximately 270 species of mushrooms have been reported as potentially useful for human health. However, few mushrooms have been studied for bioactive compounds that can be helpful in treating various diseases. Like other natural regimens, the mushroom treatment appears safe, as could be expected from their long culinary and medicinal use. This review aims to provide a critical discussion on clinical trial evidence for mushrooms to treat patients with diverse types of cancer. In addition, the review also highlights the identified bioactive compounds and corresponding mechanisms of action among the explored mushrooms. Furthermore, it also discusses mushrooms with anticancer properties, demonstrated either in vitro and/or in vivo models, which have never been tested in clinical studies. Several mushrooms have been tested in phase I or II clinical trials, mostly for treating breast cancer (18.6%), followed by colorectal (14%) and prostate cancer (11.6%). The majority of clinical studies were carried out with just 3 species: Lentinula edodes (22.2%), Coriolus versicolor, and Ganoderma lucidum (both 13.9%); followed by two other species: Agaricus bisporus and Grifola frondosa (both 11.1%). Most in vitro cell studies use breast cancer cell lines (43.9%), followed by lung (14%) and colorectal cancer cell lines (13.1%), while most in vivo animal studies are performed in mice tumor models (58.7%). Although 32 species of mushrooms at least show some promise for the treatment of cancer, only 11 species have been tested clinically thus far. Moreover, most clinical studies have investigated fewer numbers of patients, and have been limited to phase III or IV. Therefore, despite the promising preclinical and clinical data publication, more solid scientific efforts are required to clarify the therapeutic value of mushrooms in oncology.

Sesquiterpenoids Specially Produced by Fungi: Structures, Biological Activities, Chemical and Biosynthesis (2015-2020)

Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety of ecological functions, such as quorum detection, chemical defense, allelopathy, and maintenance of symbiosis. Fungi therefore remain an important resource for the screening and discovery of biologically active natural products. Sesquiterpenoids are arguably the richest natural products from plants and micro-organisms. The rearrangement of the 15 high-ductility carbons gave rise to a large number of different skeletons. At the same time, abundant structural variations lead to a diversification of biological activity. This review examines the isolation, structural determination, bioactivities, and synthesis of sesquiterpenoids that were specially produced by fungi over the past five years (2015-2020).

Recent findings on the role of fungal products in the treatment of cancer

In modern medicine, natural products have aided humans against their battles with cancer. Among these products, microorganisms, medicinal herbs and marine organisms are considered to be of great benefit. In recent decades, more than 30 fungal immunity proteins have been identified and proved to be extractable from a wide range of fungi, including mushrooms. Although chemotherapy is used to overcome cancer cells, the side effects of this method are of great concern in clinical practice. Fungal products and their derivatives constitute more than 50% of the clinical drugs currently being used globally. Approximately 60% of the clinically approved drugs for cancer treatment have natural roots. Anti-tumor immunotherapy is prospective with a rapidly growing market worldwide due to its high efficiency, immunity, and profit. Polysaccharide extracts from natural sources are being used in clinical and therapeutic trials on cancer patients. This review aims to present the latest findings in cancer treatment through isolated and extraction of fungal derivatives and other natural biomaterials.

One new sterpurane sesquiterpene from cultures of the basidiomycete Pholiota nameko

One new sterpurane sesquiterpene (1), named (3R,6S,7S,8R,10S)-3,7,14-trihydroxy-1-sterpurene was isolated from cultures of the basidiomycete Pholiota nameko. The structure of new compound was elucidated by extensive spectroscopic. Additionally, a single crystal X-ray diffraction not only confirmed the structure, but also determined the absolute configuration of the new compound. The compound was evaluated for cytotoxicity against five human cancer cell lines, but no significant cytotoxicity were found (IC₅₀ values > 40 μM).

Pholiotone A, a new polyketide derivative from Pholiota sp

Pholiotone A (1), a new polyketide derivative, with tetrahydrobenzofuran-4(2H)-one skeleton, together with four known compounds, trichodermatides A (2) and B (3) and koninginins B (4) and E (5), were isolated from the crude extract of Pholiota sp. The structures of all the isolated compounds were determined mainly by NMR experiments, the modified Mosher method and electronic circular dichroism (ECD) calculations. The antifungal and cytotoxicity of all isolates were evaluated.