Sporulosol, a New Ketal from the Fungus Paraconiothyrium sporulosum

Natural resorcylic lactones derived from alternariol

In this overview, naturally occurring resorcylic lactones biosynthetically derived from alternariol and almost exclusively produced by fungi, are discussed with view on their isolation, structure, biological activities, biosynthesis, and total syntheses. This class of compounds consists until now of 127 naturally occurring compounds, with very divers structural motifs. Although only a handful of these toxins (i.e., alternariol and its 9-O-methyl ether, altenusin, dehydroaltenusin, altertenuol, and altenuene) were frequently found and isolated as fungal contaminants in food and feed and have been investigated in significant detail, further metabolites, which were much more rarely found as natural products, similarly show interesting biological activities.

The Novel Compounds with Biological Activity Derived from Soil Fungi in the Past Decade

The secondary metabolites isolated from soil fungi have received more and more attention, especially new compounds that exhibited good biological activities. In this review, a total of 546 new compounds are included in the relevant literature since 2011. The new compounds are isolated from soil fungi, We divided these compounds into seven categories, including alkaloids, terpenoids, steroids, ketones, phenylpropanoids, quinones, esters, lactones, etc. In addition, the biological activities and structure-activity relationships of these compounds have also been fully discussed. The activities of these compounds are roughly divided into eight categories, including anticancer activity, antimicrobial activity, anti-inflammatory activity, antioxidant activity, antiviral activity, antimalarial activity, immunosuppressive activity and other activities. Since natural products are an important source of new drugs, this review may have a positive guiding effect on drug screening.

Natural Enantiomers: Occurrence, Biogenesis and Biological Properties

The knowledge that natural products (NPs) are potent and selective modulators of important biomacromolecules (e.g., DNA and proteins) has inspired some of the world's most successful pharmaceuticals and agrochemicals. Notwithstanding these successes and despite a growing number of reports on naturally occurring pairs of enantiomers, this area of NP science still remains largely unexplored, consistent with the adage "If you don't seek, you don't find". Statistically, a rapidly growing number of enantiomeric NPs have been reported in the last several years. The current review provides a comprehensive overview of recent records on natural enantiomers, with the aim of advancing awareness and providing a better understanding of the chemical diversity and biogenetic context, as well as the biological properties and therapeutic (drug discovery) potential, of enantiomeric NPs.

The genus Paraconiothyrium: species concepts, biological functions, and secondary metabolites

The genus Paraconiothyrium has worldwide distribution with diverse host habitats and exhibits potential utilisation as biocontrol agent, bioreactor and antibiotic producer. In this review, we firstly comprehensively summarise the current taxonomic status of Paraconiothyrium species, including their category names, morphological features, habitats, and multigene phylogenetic relationships. Some Paraconiothyrium species possess vital biological functions and potential applications in medicine, agriculture, industry, and environmental protection. A total of 147 secondary metabolites have been reported so far from Paraconiothyrium, among which 95 are novel. This paper serves to provide an overview of their diverse structures with chemical classification and biological activities. To date, 27 species of Paraconiothyrium have been documented; however, only seven have been investigated for their secondary metabolites or biological functions. Our review is expected to draw more attention to this genus for providing a taxonomic reference, discovering extensive biological functions, and searching in-depth for new bioactive natural products.

Antibiotic Activity of a Paraphaeosphaeria sporulosa-Produced Diketopiperazine against Salmonella enterica

A diketopiperazine has been purified from a culture filtrate of the endophytic fungus Paraphaeosphaeria sporulosa, isolated from healthy tissues of strawberry plants in a survey of microbes as sources of anti-bacterial metabolites. Its structure has been determined by nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS) analyses and was found to be identical to cyclo(L-Pro-L-Phe) purified from species of other fungal genera. This secondary metabolite has been selected following bioguided-assay fractionation against two strains of Salmonella enterica, the causal agent of bovine gastroenteritis. The diketopiperazine cyclo(L-Pro-L-Phe), isolated for the first time from Paraphaeosphaeria species, showed minimum inhibitory concentration (MIC) values of 71.3 and 78.6 μg/mL against the two S. enterica strains. This finding may be significant in limiting the use of synthetic antibiotics in animal husbandry and reducing the emergence of bacterial multidrug resistance. Further in vivo experiments of P. sporulosa diketopiperazines are important for the future application of these metabolites.

Pycnidiophorones A–D, four new cytochalasans from the wetland derived fungus Pycnidiophora dispersa

Pycnidiophorones A–D (1–4), four new cytochalasans with a rare 5/6/6/5/6 pentacyclic skeleton incorporating the unique 12-oxatricyclo[6.3.1.0^2,7]dodecane core, and six known depsidones (5–10) were isolated from cultures of the wetland-soil-derived fungus Pycnidiophora dispersa. Their chemical structures were unambiguously determined using NMR spectroscopic data. The absolute configurations of 1 and 3 were assigned by electronic circular dichroism (ECD) calculations. Compounds 1–10 showed moderate cytotoxicity against a panel of five human tumor cell lines.

Four new 5/6/6/5/6 pentacyclic cytochalasan pycnidiophorones A–D (1–4) and six known depsidones were identified from the wetland-soil-derived fungus Pycnidiophora dispersa.

Seven new Drimane-Type Sesquiterpenoids from a Marine-Derived Fungus Paraconiothyrium sporulosum YK-03

Seven new drimane-type sesquiterpenoids, namely the sporulositols A-D (1-4), 6-hydroxydiaporol (5), seco-sporulositol (6) and sporuloside (7) were isolated from the ethyl acetate extract of fermentation broth for a marine-derived fungus Paraconiothyrium sporulosum YK-03. Their structures were elucidated by analysis of extensive spectroscopic data, and the absolute configurations were established by crystal X-ray diffraction analysis and comparisons of circular dichroism data. Among them, sporulositols A-E (1-4) and seco-sporulositol (6) represent the first five examples of a unique class of drimanic mannitol derivatives, while compounds 6 and 7 may represent two new series of natural drimanes, possessing an aromatic ring with a rare 4,5-secodrimanic skeleton and an unusual CH3-15 rearranged drimanic α-D-glucopyranside, respectively. Furthermore, the origin of mannitol moiety was investigated by reliable HPLC and NMR analyses.