Insights into Ergosterol Peroxide's Trypanocidal Activity

Chemical Diversity, Pharmacology, Synthesis and Detection of Naturally Occurring Peroxides

Natural occurring peroxides are interesting bioprospecting targets due to their molecular structural diversity and the wide range of pharmacological activities. In this systematic review, a total of 123 peroxide compounds were analysed from 99 published papers with the compounds distributed in 31 plants, 18 animals and 41 microorganisms living in land and water ecosystems. The peroxide moiety exists as both cyclic and acyclic entities and can include 1,2-dioxolanes, 1,2-dioxane rings and common secondary metabolites with a peroxo group. These peroxides possessed diverse bioactivities including anticancer, antimalarial, antimicrobial, anti-inflammatory, neuroprotective, adipogenic suppressor, antituberculosis, anti-melanogenic and anti-coagulant agents. Biosynthetic pathways and mechanisms of most endoperoxides have not been well established. Method development in peroxide detection has been a challenging task requiring multidisciplinary investigation and exploration on peroxy-containing secondary metabolites are necessary.

Secondary Metabolites of Fomitopsis betulina: Chemical Structures, Biological Activity and Application Prospects

Fomitopsis betulina, as a macrofungus with both medicinal and dietary applications, is renowned for its rich content of bioactive substances. The recent advancements in research have significantly enhanced our understanding of its polysaccharides, cellulose-degrading enzymes, and wide range of secondary metabolites. This paper provides a comprehensive review of the artificial cultivation techniques and the chemical profiling of over 100 secondary metabolites identified in F. betulina, including terpenoids, phenols, and various other classes. These compounds exhibit notable pharmacological activities, such as anti-cancer, anti-inflammatory, antimicrobial, antiviral, and anti-malarial effects. Moreover, this review delves into the genomic analysis of F. betulina, focusing on the prediction and classification of terpene synthases, which play a crucial role in the biosynthesis of these bioactive compounds. This insight is instrumental for potentially facilitating future biochemical studies and pharmaceutical applications. Through this review, we aim to solidify the foundation for future in-depth studies and the development of new drugs derived from this promising natural resource.

Food and human health applications of edible mushroom by-products

Mushroom waste can account for up to 50% of the total mushroom mass. Spent mushroom substrate, misshapen mushrooms, and mushroom stems are examples of mushroom byproducts. In ancient cultures, fungi were prized for their medicinal properties. Aqueous extracts containing high levels of β-glucans as functional components capable of providing prebiotic polysaccharides and improved texture to foods have been widely used and new methods have been tested to improve extraction yields. Similarly, the addition of insoluble polysaccharides controls the glycemic index, counteracting the effects of increasingly high-calorie diets. Numerous studies support these benefits in vitro, but evidence in vivo is scarce. Nonetheless, many authors have created a variety of functional foods, ranging from yogurt to noodles. In this review, we focus on the pharmacological properties of edible mushroom by-products, and the possible risks derived from its consumption. By incorporating these by-products into human or animal feed formulations, mushroom producers will be able to fully optimize crop use and pave the way for the industry to move toward a zero-waste paradigm.

Natural endoperoxides as promising anti-leishmanials

BACKGROUND

The discovery of artemisinin, an endoperoxide, encouraged the scientific community to explore endoperoxides as potential anti-parasitic molecules. Although artemisinin derivatives are rapidly evolving as potent anti-malarials, their potential as anti-leishmanials is emerging gradually. The treatment of leishmaniasis, a group of neglected tropical diseases is handicapped by lack of effective vaccines, drug toxicities and drug resistance. The weak antioxidant defense mechanism of the Leishmania parasites due to lack of catalase and a selenium dependent glutathione peroxidase system makes them vulnerable to oxidative stress, and this has been successful exploited by endoperoxides.

PURPOSE

The study aimed to review the available literature on the anti-leishmanial efficacy of natural endoperoxides with a view to achieve insights into their mode of actions.

METHODS

We reviewed more around 110 research and review articles restricted to the English language, sourced from electronic bibliographic databases including PubMed, Google, Web of Science, Google scholar etc. RESULTS: Natural endoperoxides could potentially augment the anti-leishmanial drug library, with artemisinin and ascaridole emerging as potential anti-leishmanial agents. Due to higher reactivity of the cyclic peroxide moiety, and exploiting the compromised antioxidant defense of Leishmania, endoperoxides like artemisinin and ascaridole potentiate their leishmanicidal efficacy by creating a redox imbalance. Furthermore, these molecules minimally impair oxidative phosphorylation; instead inhibit glycolytic functions, culminating in depolarization of the mitochondrial membrane and depletion of ATP. Additionally, the carbon-centered free radicals generated from endoperoxides, participate in chain reactions that can generate even more reactive organic radicals that are toxic to macromolecules, including lipids, proteins and DNA, leading to cell cycle arrest and apoptosis of Leishmania parasites. However, the precise target(s) of the toxic free radicals remains open-ended.

CONCLUSION

In this overview, the spectrum of natural endoperoxide molecules as major anti-leishmanials and their mechanism of action has been delineated. In view of the substantial evidence that natural endoperoxides (e.g., artemisinin, ascaridole) exert a noxious effect on different species of Leishmania, identification and characterization of other natural endoperoxides is a promising therapeutic option worthy of further pharmacological consideration.

Chemical Compounds, Bioactivities, and Potential Applications of the Mushroom Species of Genus Suillus (Agaricomycetes): A Review

The genus Suillus, also known as "Song mo," falls under the order Boletales and consists of various higher fungi. It establishes mycorrhizae primarily with pine trees and has a good taste and medicinal values. Herein, we reviewed the chemical compounds present in the genus Suillus, including polysaccharides, steroids, phenols, polyprenyl phenol derivatives, fatty acids, organic acids, and amino acids, and their reported bioactivities and potential applications. This review aims to promote the utilization of the resources belonging to the genus Suillus and serves as a theoretical basis for their future studies and clinical applications.

Chemical Defence by Sterols in the Freshwater Ciliate Stentor polymorphus

Heterotrich ciliates typically retain toxic substances in specialized ejectable organelles, called extrusomes, which are used in predator-prey interactions. In this study, we analysed the chemical defence strategy of the freshwater heterotrich ciliate Stentor polymorphus against the predatory ciliate Coleps hirtus, and the microturbellarian flatworm Stenostomum sphagnetorum. The results showed that S. polymorphus is able to defend itself against these two predators by deploying a mix of bioactive sterols contained in its extrusomes. Sterols were isolated in vivo and characterized by liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR), as ergosterol, 7-dehydroporiferasterol, and their two peroxidized analogues. The assessment of the toxicity of ergosterol and ergosterol peroxide against various organisms, indicated that these sterols are essential for the effectiveness of the chemical defence in S. polymorphus.

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.

Dereplication of extracts from nutraceutical mushrooms Pleurotus using molecular network approach

Pleurotus is an edible mushroom from the well-known genus of Basidiomycetes; it is the second-most commonly consumed mushroom worldwide. This genus is characterized by the presence of steroids, fatty acids, and polysaccharides. Recently, Pleurotus has become popular as a functional food owing to its health benefits, primarily because they are a source of vitamins, fibers, minerals, and lipids. In natural products chemistry, dereplication techniques identify bioactive molecules from natural sources such as plants and fungi without isolating or characterizing molecules. We used dereplication techniques aided by the Global Natural Products Social Molecular Network to analyze the chemical composition of the methanolic extracts of six Pleurotus species (P. sapidus, P. ostreaus, P. ostreaus var. Florida, P. djamor, P. citrinopileatus, and P. pulmonarius), to identify bioactive molecules with nutraceutical properties. Using this technique, we identified several molecular families, including eight fatty acids and seven steroids. Our findings suggest that dereplication is a relatively rapid tool for characterizing fungal species and determining their nutraceutical value.

The Search for Putative Hits in Combating Leishmaniasis: The Contributions of Natural Products Over the Last Decade

Despite advancements in the areas of omics and chemoinformatics, potent novel biotherapeutic molecules with new modes of actions are needed for leishmaniasis. The socioeconomic burden of leishmaniasis remains alarming in endemic regions. Currently, reports from existing endemic areas such as Nepal, Iran, Brazil, India, Sudan and Afghanistan, as well as newly affected countries such as Peru, Bolivia and Somalia indicate concerns of chemoresistance to the classical antimonial treatment. As a result, effective antileishmanial agents which are safe and affordable are urgently needed. Natural products from both flora and fauna have contributed immensely to chemotherapeutics and serve as vital sources of new chemical agents. This review focuses on a systematic cross-sectional view of all characterized anti-leishmanial compounds from natural sources over the last decade. Furthermore, IC50/EC50, cytotoxicity and suggested mechanisms of action of some of these natural products are provided. The natural product classification includes alkaloids, terpenes, terpenoids, and phenolics. The plethora of reported mechanisms involve calcium channel inhibition, immunomodulation and apoptosis. Making available enriched data pertaining to bioactivity and mechanisms of natural products complement current efforts geared towards unraveling potent leishmanicides of therapeutic relevance.

Interaction of a Novel Zn2Cys6 Transcription Factor DcGliZ with Promoters in the Gliotoxin Biosynthetic Gene Cluster of the Deep-Sea-Derived Fungus Dichotomomyces cejpii

Gliotoxin is an important epipolythiodioxopiperazine, which was biosynthesized by the gli gene cluster in Aspergillus genus. However, the regulatory mechanism of gliotoxin biosynthesis remains unclear. In this study, a novel Zn2Cys6 transcription factor DcGliZ that is responsible for the regulation of gliotoxin biosynthesis from the deep-sea-derived fungus Dichotomomyces cejpii was identified. DcGliZ was expressed in Escherichia coli and effectively purified from inclusion bodies by refolding. Using electrophoretic mobility shift assay, we demonstrated that purified DcGliZ can bind to gliG, gliM, and gliN promoter regions in the gli cluster. Furthermore, the binding kinetics and affinity of DcGliZ protein with different promoters were measured by surface plasmon resonance assays, and the results demonstrated the significant interaction of DcGliZ with the gliG, gliM, and gliN promoters. These new findings would lay the foundation for the elucidation of future gliotoxin biosynthetic regulation mechanisms in D. cejpii.