Chemical constituents from a marine medicinal brown alga-derived Xylaria acuta SC1019.

In this study, a marine medicinal brown alga Sargassum cristaefolium-derived fungal strain Xylaria acuta SC1019 was isolated and identified. Column chromatography of the extracts from liquid- and solid-fermented products of the fungal strain was carried out, and led to the isolation of twenty-one compounds. Their structures were characterized by spectroscopic analysis, and the absolute configurations were further established by single X-ray diffraction analysis or modified Mosher's method as nine previously undescribed compounds, namely xylarilactones A-C (1-3), ent-gedebic acid 8-O-α-D-glucopyranoside (4), 5R-hydroxylmethylmellein 11-O-α-D-glucopyranoside (5), ent-hymatoxin E 16-O-α-D-mannopyranoside (6), 19,20-epoxycytochalasin S (7), 19,20-epoxycytochalasin T (8), and (2R)-butylitaconic acid (9), along with twelve known compounds 10-21. All the isolates were subjected to anti-inflammatory and anti-angiogenic assays. Compounds 1, 5, 7, 10, and 17 showed moderate nitric oxide production inhibitory activities in lipopolysaccharide-activated BV-2 microglial cells with IC50 values of 19.55 ± 0.35, 16.10 ± 0.57, 15.20 ± 0.87, 11.76 ± 0.49, and 11.30 ± 0.32 µM, respectively, as compared to curcumin (IC50 = 2.69 ± 0.34 µM) without any significant cytotoxicity. Compounds 7, 8, and 21 displayed potent anti-angiogenic activities by suppressing the growth of human endothelial progenitor cells with IC50 values of 0.44 ± 0.01, 0.47 ± 0.03, and 0.53 ± 0.01 µM, respectively, as compared to sorafenib (IC50 = 5.50 ± 1.50 µM).

Xylarkarynone A and B: Two Bioactive Eremophilane Sesquiterpenes from Xylaria sp. HHY-2.

A new compound xylarkarynone A (1), a first reported natural product compound xylarkarynone B (2) and eight known compounds (3-10) were isolated from Xylaria sp. HHY-2. Their structures were elucidated by spectroscopic methods, DP4+ probability analyses and electronic circular dichroism (ECD) calculations. The bioactivities of isolated compounds were assayed. Compound 1 exhibited obvious activity against A549 cells with an IC50 value of 6.12±0.28 µM. Additionally, compound 1 showed moderate antifungal activities against Plectosphaerella cucumerina and Aspergillus niger with minimum inhibitory concentrations (MICs) of both 16 µg/mL, which was at the same grade with positive control nystatin. Most compounds exhibited varying degrees of inhibitory activity against P. cucumerina, indicating that Xylaria sp. has potential as inhibitors against P. cucumerina.

New Pyranone Derivatives and Sesquiterpenoid Isolated from the Endophytic Fungus Xylaria sp. Z184.

The fungus Xylaria sp. Z184, harvested from the leaves of Fallopia convolvulus (L.) Á. Löve, has been isolated for the first time. Chemical investigation on the methanol extract of the culture broth of the titles strain led to the discovery of three new pyranone derivatives, called fallopiaxylaresters A-C (1-3), and a new bisabolane-type sesquiterpenoid, named fallopiaxylarol A (4), along with the first complete set of spectroscopic data for the previously reported pestalotiopyrone M (5). Known pyranone derivatives (6-11), sesquiterpenoids (12-14), isocoumarin derivatives (15-17), and an aromatic allenic ether (18) were also co-isolated in this study. All new structures were elucidated by the interpretation of HRESIMS, 1D, 2D NMR spectroscopy, and quantum chemical computation approach. The in vitro antimicrobial, anti-inflammatory, and α-glucosidase-inhibitory activities of the selected compounds and the crude extract were evaluated. The extract was shown to inhibit nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine RAW264.7 macrophage cells, with an inhibition rate of 77.28 ± 0.82% at a concentration of 50 µg/mL. The compounds 5, 7, and 8 displayed weak antibacterial activity against Staphylococcus areus subsp. aureus at a concentration of 100 µM.

Chaetoxylariones A-G: undescribed chromone-derived polyketides from co-culture of Chaetomium virescens and Xylaria grammica enabled via the molecular networking strategy.

By co-culturing two endophytic fungi (Chaetomium virescens and Xylaria grammica) collected from the medicinal and edible plant Smilax glabra Roxb. and analyzing them with MolNetEnhancer module on GNPS platform, seven undescribed chromone-derived polyketides (chaetoxylariones A-G), including three pairs of enantiomer ones (2a/2b, 4a/4b and 6a/6b) and four optical pure ones (1, 3, 5 and 7), as well as five known structural analogues (8-12), were obtained. The structures of these new compounds were characterized by NMR spectroscopy, single-crystal X-ray diffraction, 13C NMR calculation and DP4+ probability analyses, as well as the comparison of the experimental electronic circular dichroism (ECD) data. Structurally, compound 1 featured an unprecedented chromone-derived sulfonamide tailored by two isoleucine-derived δ-hydroxy-3-methylpentenoic acids via the acylamide and NO bonds, respectively; compound 2 represented the first example of enantiomeric chromone derivative bearing a unique spiro-[3.3]alkane ring system; compound 3 featured a decane alkyl side chain that formed an undescribed five-membered lactone ring between C-7' and C-10'; compound 4 contained an unexpected highly oxidized five-membered carbocyclic system featuring rare adjacent keto groups; compound 7 featured a rare methylsulfonyl moiety. In addition, compound 10 showed a significant inhibition towards SW620/AD300 cells with an IC50 value of PTX significantly decreased from 4.09 µM to 120 nM, and a further study uncovered that compound 10 could obviously reverse the MDR of SW620/AD300 cells.

Rosellichalasins A-H, cytotoxic cytochalasans from the endophytic fungus Rosellinia sp. Glinf021.

Eight new cytochalasans rosellichalasins A-H (1-8), as well as two new shunt metabolites rosellinins A (9) and B (10) before intramolecular Diels-Alder cycloaddition reaction in cytochalasan biosynthesis, along with nine known cytochalsans (11-19) were isolated from the endophytic fungus Rosellinia sp. Glinf021, which was derived from the medicinal plant Glycyrrhiza inflata. Their structures were characterized by extensive analysis of 1D and 2D NMR as well as HRESIMS spectra and quantum chemical ECD calculations. The cytotoxic activities of these compounds were evaluated against four human cancer cell lines including HCT116, MDA-MB-231, BGC823, and PANC-1 with IC50 values ranging from 0.5 to 58.2 µM.

Two new quinoline alkaloid with neuroprotective activities from Xylaria longipes.

Two new quinoline alkaloids with an α, ß-unsaturated amide side chain, xylarinines A and B (1 and 2), were isolated from the ethyl acetate extracts of Xylaria longipes solid fermentation. The structures of these were primarily determined though NMR and HRESIMS data analysis. The absolute configuration of compound 1 was assigned using experimental and calculated ECD data. The neuroprotective effects of compounds 1 and 2 against glutamate-induced damage in PC12 cells were evaluated in vitro bioassay. The results demonstrated that both compounds significantly improved cell viability, inhibited apoptosis, decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione (GSH) levels, and reduced intracellular reactive oxygen species (ROS) accumulation. These findings suggested that these mechanisms contribute to the neuroprotective effects of the compounds.

Comparative Mitogenomics Analysis Revealed Evolutionary Divergence among Neopestalotiopsis Species Complex (Fungi: Xylariales).

The genus Neopestalotiopsis consists of obligate parasites that cause ring spot, scab, and leaf blight diseases in higher plant species. We assembled the three complete mitogenomes for the guava fruit ring spot pathogen, Neopestalotiopsis cubana. The mitogenomes are circular, with sizes of 38,666 bp, 33,846 bp, and 32,593 bp. The comparative analyses with Pestalotiopsis fici showed that N. cubana differs greatly from it in the length of the mitogenomes and the number of introns. Moreover, they showed significant differences in the gene content and tRNAs. The two genera showed little difference in gene skewness and codon preference for core protein-coding genes (PCGs). We compared gene sequencing in the mitogenomes of the order Xylariales and found large-scale gene rearrangement events, such as gene translocations and the duplication of tRNAs. N. cubana shows a unique evolutionary position in the phylum Ascomycota constructed in phylogenetic analyses. We also found a more concentrated distribution of evolutionary pressures on the PCGs of Neopestalotiopsis in the phylum Ascomycota and that they are under little selective pressure compared to other species and are subjected to purifying selection. This study explores the evolutionary dynamics of the mitogenomes of Neopestalotiopsis and provides important support for genetic and taxonomic studies.

Phylogenetic analysis of Microdochium spp. associated with turfgrass and their pathogenicity in cereals.

Turfgrass is frequently used today in the arrangement and aesthetic beautification of grounds in parks, gardens, median strips, recreation and sports areas. In this study, surveys were conduct in turfgrass areas in the three provinces of Türkiye. As a result of isolations from the collected samples, 44 Microdochium isolates obtained belonging to five different species including M. bolleyi, M. majus, M. nivale, M. paspali and M. sorghi which have different virulences. Identification of the isolates were performed by rDNA-ITS sequence analyzes. According to the pathogenicity tests results, the most virulent species was M. nivale M62 with a disease severity value of 91.93%. This was followed by M. bolleyi M1584 and M. majus M63, with disease severity values of 91.12% and 91.08%, respectively. The virulence of M. bolleyi isolates varied among the species. Only 13 of the 31 M. bolleyi species were found to be virulent in turfgrass, M. paspali was less virulent than the others in Poa pratensis. The most virulent isolate of each Microdochium species was tested on four different cereal varieties. M. sorghi and M. paspali had low virulence values in barley and oat than the other Microdochium species, while the other three species showed high virulence in turfgrass, wheat and barley, other than oat. In the phylogenetic neighboor-joining tree belonging to 44 Microdochium isolates clearly demonstrated that the isolates were grouped into five distinct clusters. M. nivale and M. majus were considered genetically close isolates.

Novel Pestalotiopsis that Causes Gray Spot Disease of Polygonatum cyrtonema in Hunan Province of China.

Polygonatum cyrtonema Hua is a perennial herb of the Asparagaceae family that is used for both dietary and medicinal purposes in China. In September 2019, a new leaf spot disease on Polygonatum cyrtonema was detected and is currently widespread in Huaihua, Hunan Province, China. Pathogenic fungi were isolated and purified from samples of diseased tissue that were collected for morphological and molecular phylogenetic studies. The pathogen was identified using multilocus (ITS, TEF-1, and TUB2) phylogenies, as well as morphological characters, and was found to be clustered but separately divergent from species of Pestalotiopsis. However, there were significant morphological differences between the pathogen and similar species. The pathogen was finally identified as a new species that was designated Pestalotiopsis xuefengensis. This is the first report of Pestalotiopsis xuefengensis serving as the causal agent of gray leaf spot on Polygonatum cyrtonema. This study will provide useful information for the diagnosis and management of this disease.

New sesquiterpenoids from Biscogniauxia sp.

Five new sesquiterpenoids, including a campherenane-type (1), a bergamotane-type (2), a drimane-type (3), and two bisabolane-type (5-6) sesquiterpenoids have been isolated from Biscogniauxia sp. 71-10-1-1. Their structures were determined by spectroscopic analyses, quantum chemical ECD calculations,13C chemical shifts calculations, and X-ray crystallography. This is the first report of campherenane-type and drimane-type sesquiterpenoids from Biscogniauxia. Furthermore, the anti-inflammatory assays of all compounds are evaluated, and the results showed that compounds 3 and 7 exhibited the effects against the production of the pro-inflammatory cytokine TNF-α.

Xylarcurcosides A-C, three novel isopimarane-type diterpene glycosides from Xylaria curta YSJ-5.

Three previously undescribed isopimarane-type diterpene glycosides named as xylarcurcosides A-C (1-3) along with two known ones 16-α-d-mannopyranosyloxyisopimar-7-en-19-oic acid (4) and hypoxylonoid A (5) were successfully isolated from an ethyl acetate extract of the endophytic fungus Xylaria curta YSJ-5 growing in leaves of Alpinia zerumbet. The spectroscopic methods, electronic circular dichroism (ECD) calculations, and X-ray diffraction experiments were conducted to identify their absolute chemical structures. All these compounds were tested for in vitro cytotoxic, anti-inflammatory, α-glucosidase inhibitory, and antibacterial activities. As a result, these novel compounds demonstrated no obvious cytotoxic and antibacterial activity.

Assessment of the photoprotective potential and structural characterization of secondary metabolites of Antarctic fungus Arthrinium sp.

Interest in Antarctic fungi has grown due to their resilience in harsh environments, suggesting the presence of valuable compounds from its organisms, such as those presenting photoprotective potential, since this environment suffers the most dangerous UV exposure in the world. Therefore, this research aimed to assess the photoprotective potential of compounds from sustainable marine sources, specifically seaweed-derived fungi from Antarctic continent. These studies led to discovery of photoprotective and antioxidant properties of metabolites from Arthrinium sp., an endophytic fungus from Antarctic brown algae Phaeurus antarcticus. From crude extract, fractions A-I were obtained and compounds 1-6 isolated from E and F fractions, namely 3-Hydroxybenzyl alcohol (1), (-)-orthosporin (2), norlichexanthone (3), anomalin B (4), anomalin A (5), and agonodepside B (6). Compounds 1, 2, and 6 were not previously reported in Arthrinium. Fraction F demonstrated excellent absorbance in both UVA and UVB regions, while compound 6 exhibited lower UVB absorbance, possibly due to synergistic effects. Fraction F and compound 6 displayed photostability and were non-phototoxic to HaCaT cells. They also exhibited antioxidant activity by reducing intracellular ROS production induced by UVA in keratinocyte monolayers and reconstructed human skin models (resulting in 34.6% and 30.2% fluorescence reduction) and did not show irritation potential in HET-CAM assay. Thus, both are promising candidates for use in sunscreens. It is noted that Fraction F does not require further purification, making it advantageous, although clinical studies are necessary to confirm its potential applicability for sunscreen formulations.

Arthproliferins A-D, Four New Sesterterpenes from the Mangrove-Sediment-Derived Fungus Arthrinium sp. SCSIO41221.

Four new sesterterpenes, arthproliferins A-D (1-4), together with four known derivatives, were isolated and characterized from the mangrove-sediment-derived fungus Arthrinium sp. SCSIO41221. Their structures were determined using detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses. Some of the isolated compounds were evaluated for their cytotoxicity in vitro. The results revealed that terpestacin (6) exhibited significant activity with an IC50 value of 20.3 µM, and compounds 2 and 5 were found to show weak inhibitory effects against U87MG-derived GSCs.

Pimarane-Type Diterpenes with Anti-Inflammatory Activity from Arctic-Derived Fungus Eutypella sp. D-1.

The Arctic-derived fungus Eutypella sp. D-1 can produce numerous secondary metabolites, and some compounds exhibit excellent biological activity. Seven pimarane-type diterpenes, including three new compounds eutypellenone F (1), libertellenone Y (2), and libertellenone Z (3), and four known compounds (4-7), were isolated from fermentation broth of Eutypella sp. D-1 by the OSMAC strategy of adding ethanol as a promoter in the culture medium. Compound 2 has a rare tetrahydrofuran-fused pimarane diterpene skeleton. The anti-inflammatory activity of all compounds was evaluated. Compounds 3-6 showed a significant inhibitory effect on cell NO release at 10 µmol/L by in vitro experiments, of which 3-5 had inhibitory rates over 60% on nitric oxide (NO) release. Subsequently, the anti-inflammatory activity of 3-5 was evaluated based on a zebrafish model, and the results showed that 3 had a significant inhibitory effect on inflammatory cells migration at 40 µmol/L, while 4 and 5 had a significant inhibitory effect at 20 µmol/L. Moreover, compounds 3-5 have the same conjugated double bond structure, which may be an important group for these compounds to exert anti-inflammatory activity.

Phylogenetic relationships of the woodlouse flies (Diptera: Rhinophorinae) and the cluster flies (Diptera: Polleniidae).

Phylogenetic relationships within the oestroid subclades Rhinophorinae (Calliphoridae) and Polleniidae were reconstructed for the first time, applying a Sanger sequencing approach using the two protein-coding nuclear markers CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase; 1794 bp) and MCS (molybdenum cofactor sulfurase; 2078 bp). Three genera of Polleniidae and nineteen genera of Rhinophorinae were analyzed together with a selection of taxa representing the major lineages of Oestroidea (non-rhinophorine Calliphoridae, Oestridae, Sarcophagidae, Tachinidae). The selected markers provide good resolution and moderate to strong support of the distal branches, but weak support for several deeper nodes. Polleniidae (cluster flies) emerge as monophyletic and their sister-group relationship to Tachinidae is confirmed. Morinia Robineau-Desvoidy as currently circumscribed emerges as paraphyletic with regard to Melanodexia Williston, and Pollenia Robineau-Desvoidy is the sister taxon of the Morinia-Melanodexia clade. We propose a classification with two subfamilies, Moriniinae Townsend (including Morinia, Melanodexia, and Alvamaja Rognes), and Polleniinae Brauer & Bergenstamm (including Pollenia, Dexopollenia Townsend, and Xanthotryxus Aldrich). Anthracomyza Malloch and Nesodexia Villeneuve are considered as Oestroidea incertae sedis pending further study. Rhinophorinae (woodlouse flies) emerge as monophyletic and sister to a clade composed of (Ameniinae + (Ameniinae + Phumosiinae)), and a tribal classification is proposed with the subfamily divided into Rhinophorini Robineau-Desvoidy, 1863 and Phytonini Robineau-Desvoidy, 1863 (the Stevenia-group and the Phyto-group of authors, respectively). Oxytachina Brauer & Bergenstamm, 1891, stat. rev. is resurrected to contain nine Afrotropical rhinophorine species currently assigned to genus Rhinomorinia Brauer & Bergenstamm, 1891: Oxytachina approximata (Crosskey, 1977) comb. nov., O. atra (Bischof, 1904) comb. nov., O. bisetosa (Crosskey, 1977) comb. nov., O. capensis (Brauer & Bergenstamm, 1893) comb. nov., O. scutellata (Crosskey, 1977) comb. nov., O. setitibia (Crosskey, 1977) comb. nov., O. verticalis (Crosskey, 1977) comb. nov., O. vittata Brauer & Bergenstamm, 1891, and O. xanthocephala (Bezzi, 1908) comb. nov.

CoMFA Directed Molecular Design for Significantly Improving Fungicidal Activity of Novel [1,2,4]-Triazolo-[3,4-b][1,3,4]-thiadizoles.

Target based molecular design via the aid of computation is one of the most efficient methods in the discovery of novel pesticides. Here, a combination of the comparative molecular field analysis (CoMFA) and molecular docking was applied for discovery of potent fungicidal [1,2,4]-triazolo-[3,4-b][1,3,4]-thiadiazoles. Bioassay results indicated that the synthesized target compounds 3a, 3b, and 3c exhibited good activity against Alternaria solani, Botrytis cinerea, Cercospora arachidicola, Fusarium graminearum, Physalospora piricola, Rhizoctonia solani, and Sclerotinia sclerotiorum with an EC50 value falling between 0.64 and 16.10 µg/mL. Specially, 3c displayed excellent fungicidal activity against C. arachidicola and R. solani, which was 5 times more potent than the lead YZK-C22. The enzymatic inhibition assay and fluorescence quenching analysis with R. solani pyruvate kinase (RsPK) showed a weaker binding affinity between RsPK and 3a, 3b, or 3c. Transcriptomic analyses showed that 3c exerted its fungicidal activity by disrupting steroid biosynthesis and ribosome biogenesis in eukaryotes. These findings support that 3c is a promising fungicide candidate, and a fine modification from a lead may lead to a totally different mode of action.

Discovery of Naphthol Tetramers from Endolichenic Fungus Daldinia childiae 047219 Based on MS/MS Molecular Networking.

Feature-based molecular networking analysis suggested the presence of naphthol tetramers in Daldinia childae 047219, the same species but a different strain from one used previously for the discovery of naphthol trimers promoting adiponectin synthesis. The new tetramers were composed of 5-methoxy-4-naphthol, each of which was connected to one another in various positions. Targeted isolation afforded six previously unreported naphthol tetramers (1-6) together with 13 known polyketides (7-19) including naphthol monomers, dimers, and trimers. Structures of the isolated compounds were established by using NMR and mass spectroscopic analysis. Nodulisporin A (13), nodulisporin B (14), and 1,1',3',3″-ternaphthalene-5,5',5″-trimethoxy-4,4',4″-triol (16) demonstrated anti-inflammatory activities against NO production, but the new compounds were less active.

Cytosporin Derivatives from Arctic-Derived Fungus Eutypella sp. D-1 via the OSMAC Approach.

A chemical investigation of the Arctic-derived fungus Eutypella sp. D-1 based on the OSMAC (one strain many compounds) approach resulted in the isolation of five cytosporin polyketides (compounds 1-3 and 11-12) from rice medium and eight cytosporins (compounds 2 and 4-11) from solid defined medium. The structures of the seven new compounds, eutypelleudesmane A (1), cytosporin Y (2), cytosporin Z (3), cytosporin Y1 (4), cytosporin Y2 (5), cytosporin Y3 (6), and cytosporin E1 (7), were elucidated by analyzing their detailed spectroscopic data. Structurally, cytosporin Y1 (4) may be a key intermediate in the biosynthesis of the isolated cytosporins, rather than an end product. Compound 1 contained a unique skeleton formed by the ester linkage of two moieties, cytosporin F (12) and the eudesmane-type sesquiterpene dihydroalanto glycol. Additionally, the occurrence of cyclic carbonate moieties in compounds 6 and 7 was found to be rare in nature. The antibacterial, immunosuppressive, and cytotoxic activities of all compounds derived from Eutypella sp. D-1 were evaluated. Unfortunately, only compounds 3, 6, 8, and 10-11 displayed immunosuppressive activity, with inhibitory rates of 62.9%, 59.5%, 67.8%, 55.8%, and 68.7%, respectively, at a concentration of 5 µg/mL.

Polyketide- and Terpenoid-Derived Metabolites Produced by a Marine-Derived Fungus, Peroneutypa sp.

Bioassay-guided investigation of the EtOAc-soluble extract of a culture of the marine-derived fungus Peroneutypa sp. M16 led to the isolation of seven new polyketide- and terpenoid-derived metabolites (1, 2, 4-8), along with known polyketides (3, 9-13). Structures of compounds 1, 2, and 4-8 were established by analysis of spectroscopic data. Absolute configurations of compounds 1, 2, 4, 6, 7, and 8 were determined by the comparison of experimental ECD spectra with calculated CD data. Compound 5 exhibited moderate antiplasmodial activity against both chloroquine-sensitive and -resistant strains of Plasmodium falciparum.

Molecular detection and identification of Diatrypaceous airborne spores in Australian vineyards revealed high species diversity between regions.

The grapevine trunk disease, Eutypa dieback (ED), causes significant vine decline and yield reduction. For many years, the fungus Eutypa lata was considered the main pathogen causing ED of grapevines in Australia. Recent studies showed other Diatrypaceous fungi were also associated with vines exhibiting dieback symptoms but there is limited information on how these fungal pathogens spread in vineyards. Thus, information on the spore dispersal patterns of Diatrypaceous fungi in different wine regions will assist in identifying high-risk infection periods in vineyards. Using more than 6800 DNA samples from airborne spores collected from eight wine regions in south-eastern Australia over 8 years using a Burkard spore trap, this study investigated the diversity and abundance of Diatrypaceous species, using multi-faceted molecular tools. A multi-target quantitative PCR (qPCR) assay successfully detected and quantified Diatrypaceous spores from 30% of the total samples with spore numbers and frequency of detection varying between regions and years. The high-resolution melting analysis (HRMA) coupled with DNA sequencing identified seven species, with E. lata being present in seven regions and the most prevalent species in the Adelaide Hills, Barossa Valley and McLaren Vale. Cryptovalsa ampelina and Diatrype stigma were the predominant species in the Clare Valley and Coonawarra, respectively while Eutypella citricola and Eu. microtheca dominated in the Hunter Valley and the Riverina regions. This study represents the first report of D. stigma and Cryptosphaeria multicontinentalis in Australian vineyards. This study further showed rainfall as a primary factor that triggers spore release, however, other weather factors that may influence the spore release in different climatic regions of Australia still requires further investigation.