Xylariaceae Research Articles

Secondary Metabolites of Biscogniauxia: Distribution, Chemical Diversity, Bioactivity, and Implications of the Occurrence.

The genus Biscogniauxia, a member of the family Xylariaceae, is distributed worldwide with more than 50 recognized taxa. Biscogniauxia species is known as a plant pathogen, typically acting as a parasite on tree bark, although certain members of this genus also function as endophytic microorganisms. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites. Currently, there are a total of 115 chemical compounds belonging to the class of secondary metabolites, and among these compounds, fatty acids have been identified. In addition, the strong pharmacological agents of this genus are (3aS,4aR,8aS,9aR)-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto [2,3-b]furan-2(3H)-one (HDFO) (antifungal), biscopyran (phytotoxic activity), reticulol (antioxidant), biscogniazaphilone A and B (antimycobacterial), and biscogniauxone (Enzyme GSK3 inhibitor). This comprehensive research contributes significantly to the potential discovery of novel drugs produced by Biscogniauxia and holds promise for future development. Importantly, it represents the first-ever review of natural products originating from the Biscogniauxia genus.

Eremophilanolide sulfoxides and eremophilanolides from the mangrove fungus TBRC-BCC 64093

Two unusual eremophilanolide sulfoxide diastereomers (1 and 2), seven eremophilanolides (3–7, 11, and 12) together with nine known eremophilanolides (8–10 and 13–18), anserinone A (19), and (−)-mellein-5-carboxylic acid (20) were isolated from the mangrove fungus TBRC-BCC 64093, a member of family Xylariaceae. The structures of these compounds were elucidated by extensive spectroscopic analysis of their NMR and MS data. The absolute configurations of the eremophilane sulfoxide diastereomers were determined by comparison of experimental and calculated electronic circular dichroism (ECD) data by TDDFT. Among the tested metabolites, eremophilane sulfoxide 1 showed weak cytotoxic activity against Vero cell lines with an IC50 value of 17.7 μg/mL.

Endophytic Fungus of Achyrocline satureioides: Molecular Identification, Chemical Characterization, and Cytotoxic Evaluation of its Metabolites in Human Melanoma cell line.

Endophytic fungi are important sources of anticancer compounds. An endophytic fungus was isolated from the medicinal plant Achyrocline satureioides, and molecularly identified as Biscogniauxia sp. (family Xylariaceae) based on partial nucleotide sequences of the internal transcribed spacer genomic region (GenBank Accession No. ON257911). The chemical characterization and cytotoxic properties of secondary metabolites produced by Biscogniauxia sp. were evaluated in a human melanoma cell line (A375). The fungus was grown in potato-dextrose liquid medium for 25 days, and the extracted compounds were subjected to solid-phase fractionation to obtain the purified FDCM fraction, for which the metabolites were elucidated via ultra-performance chromatography coupled to a mass spectrometer. In the present study, 17 secondary metabolites of Biscogniauxia sp., including nine polyketide derivatives, five terpenoids, and three isocoumarins, were putatively identified. This is the first study to report of the ability of Biscogniauxia sp. in the production of isocoumarin orthosporin; the terpenoids nigriterpene A and 10-xylariterpenoid; the polyketide derivatives daldinin C, 7'dechloro-5'-hydroxygriseofulvin, daldinone D, Sch-642305, curtachalasin A, cytochalasin E, epoxycytochalasins Z8, Z8 isomer, and Z17. Furthermore, this study has reported the biosynthesis of Sch-642305 by a Xylariaceae fungus for the first time. FDCM significantly reduced the viability and proliferation of human melanoma cells at half-maximal inhibitory concentrations ​​of 10.34 and 6.89µg/mL, respectively, and induced late apoptosis/necrosis and cell cycle arrest in G2/M phase after 72h of treatment. Given its ability to produce unique metabolites with promising cytotoxic effects, Biscogniauxia sp. of A. satureioides may be a reservoir of compounds with important therapeutic applications.

Metabolic Diversity of Xylariaceous Fungi Associated with Leaf Litter Decomposition.

Fungi in the family Xylariaceae are primary agents of leaf litter decomposition. However, the diversity of carbon source utilization by xylariaceous fungi and the relative effects on this from environmental and phylogenetic factors are largely unknown. This study assessed the metabolic diversity and redundancy of xylariaceous fungi, associated with leaf litter decomposition, by measuring their in vitro capacity to utilize multiple carbon sources. The work identified the relative influences of geographic and climatic sources, as well as the taxonomic and phylogenetic relatedness, of the fungi. Using Biolog EcoPlateTM, 43 isolates belonging to Nemania, Xylaria, Nodulisporium, Astrocystis, and Hypoxylon, isolated from Castanopsis sieboldii leaf litter at eight sites in Japan, were found to have the capacity to utilize a variety of carbohydrates, amino acids/amines, carboxylic acids, and polymers. The genera of xylariaceous fungi and their origins significantly affected their metabolic diversity and utilization of carbon sources. Variation partitioning demonstrated that dissimilarities in carbon utilization among fungal isolates were mostly attributable to site differences, especially climatic factors: mean annual temperature and precipitation, and maximum snow depth. Moreover, xylariaceous isolates that originated from adjacent sites tended to have similar patterns of carbon source utilization, suggesting metabolic acclimation to local environmental conditions.

Cultivable Fungal Endophytes in Roots, Rhizomes and Leaves of Posidonia oceanica (L.) Delile along the Coast of Sicily, Italy.

The presence of endophytic fungi in the roots, rhizomes, and leaves of Posidonia oceanica was evaluated in different localities of the Sicilian coast. Samples of roots, rhizomes, and leaves were submitted to isolation techniques, and the obtained fungal colonies were identified by morphological and molecular (rRNA sequencing) analysis. Fungal endophytes occurred mainly in roots and occasionally in rhizomes and leaves. Lulwoana sp. was the most frequent of the isolated taxa, suggesting a strong interaction with the host. In addition, eight other fungal taxa were isolated. In particular, fungi of the genus Ochroconis and family Xylariaceae were identified as endophytes in healthy plants at all sampling stations, whereas Penicillium glabrum was isolated at only one sampling station. Thus, several organs, especially roots of Posidonia oceanica, harbor endophytic fungi, potentially involved in supporting the living host as ascertained for terrestrial plants.

Secondary Metabolites from Annulohypoxylon sp. and Structural Revision of Emericellins A and B.

Seven previously undescribed compounds were isolated from the endophytic fungus Annulohypoxylon sp. KYG-19 (family Xylariaceae), including three gymnomitrane-type sesquiterpenes xylariacinols A, B, and D (1, 2, and 4), one bisabolane-type sesquiterpene annulnol F (6), one phenol derivative lariacinol G (7), and two polyhydroxy compounds hypoxylonols H and I (8 and 9), together with two known gymnomitrane-type sesquiterpenes emericellin A (3) and 3-gymnomitren-15-ol (5). The assignments of their structures was determined by extensive spectroscopic and spectrometric analysis, acetonide analysis, Mosher's method, and X-ray crystallography. In addition, the structures of emericellins A and B, which were reported to possess an unprecedented tricyclo[4, 4, 2, 1]hendecane scaffold, were revised by comparing their spectroscopic data with those of 1 and 3. Compounds 1 and 4 exhibited antibacterial activity against Escherichia coli with minimum inhibitory concentrations of 4 and 2 μg/mL, respectively.

Endolichenic fungi from common Usnea lichens found in a montane forest in Malaysia: a study on diversity and bioactivity profiling

This study evaluated the diversity of endolichenic fungi (ELF) isolated from three common lichen species (Usnea baileyi, U. bismolliuscula and U. pectinata) found in Bukit Larut, Peninsular Malaysia. Diversity indices and phylogenetic analysis were performed to identify the various species found in lichens, and their bioactivity profiles were established based on antimicrobial and antioxidant activities. Sixty-two (62) ELF isolates were identified, mostly belonging to the family Xylariaceae (88.7%, 55 isolates), followed by Hypoxylaceae (6.5%, four isolates), Nectriaceae (3.2%, two isolates) and Sporocadaceae (1.6%, one isolate). The common genera were Nemania (45.2%, 28 isolates) and Xylaria (27.4%, 17 isolates). In this study, ELF isolates have shown both host-generalist and host-specific behaviours towards their lichen hosts. The ELF also have relatively strong antimicrobial (minimum inhibitory concentration:0.0625-10.00mg/ml) and antioxidant (IC50:5.72-17.8mg/ml) properties. This study highlights that a diverse ELF collection rich in bioactive compounds can be found in lichens in the montane forest in Malaysia.

Volatile Constituents of Endophytic Fungi Isolated from Aquilaria sinensis with Descriptions of Two New Species of Nemania.

Algae, bacteria, and fungi, as well as higher plants, produce a wide variety of secondary metabolites known as natural products. Natural products are well known as remarkable sources of many therapeutic agents. The genus Nemania is a wood-decaying fungus that belongs to family Xylariaceae. Nemania is often found as an endophyte in diverse hosts and some species are known to produce useful secondary metabolites. In this study, two Nemania species were isolated as an endophytic fungus from Aquilaria sinensis. Multi-gene phylogenetic studies showed that the newly described strains of Nemania are new to science, and this is the first report of Nemania from the host Aquilaria. One of the fermented species, Nemania aquilariae (KUMCC 20-0268), resulted in five sesquiterpenoids, which were previously reported from agarwood, and their structures were identified by gas chromatography-mass spectrometry (GC-MS). In addition, five different media were investigated in vitro to optimize conditions for growing the fungal biomass of Nemania aquilariae and N. yunnanensis.

Xylaria necrophora, sp. nov., is an emerging root-associated pathogen responsible for taproot decline of soybean in the southern United States

ABSTRACT Taproot decline (TRD) is a disease of soybean that has been reported recently from the southern United States (U.S.). Symptoms of TRD include foliar interveinal chlorosis followed by necrosis. Darkened, charcoal-colored areas of thin stromatic tissue are evident on the taproot and lateral roots along with areas of necrosis within the root and white mycelia within the pith. Upright stromata typical of Xylaria can be observed on crop debris and emerging from infested roots in fields where taproot decline is present, but these have not been determined to contain fertile perithecia. Symptomatic plant material was collected across the known range of the disease in the southern U.S., and the causal agent was isolated from roots. Four loci, ⍺-actin (ACT), β-tubulin (TUB2), the nuclear rDNA internal transcribed spacers (nrITS), and the RNA polymerase subunit II (RPB2), were sequenced from representative isolates. Both maximum likelihood and Bayesian phylogenetic analyses showed consistent clustering of representative TRD isolates in a highly supported clade within the Xylaria arbuscula species complex in the “HY” clade of the family Xylariaceae, distinct from any previously described taxa. In order to understand the origin of this pathogen, we sequenced herbarium specimens previously determined to be “Xylaria arbuscula” based on morphology and xylariaceous endophytes collected in the southern U.S. Some historical specimens from U.S. herbaria collected in the southern region as saprophytes as well as a single specimen from Martinique clustered within the “TRD” clade in phylogenetic analyses, suggesting a possible shift in lifestyle. The remaining specimens that clustered within the family Xylariaceae, but outside of the “TRD” clade, are reported. Both morphological evidence and molecular evidence indicate that the TRD pathogen is a novel species, which is described as Xylaria necrophora.

Phylogenetic and Chemotaxonomic Studies Confirm the Affinities of Stromatoneurospora phoenix to the Coprophilous Xylariaceae.

The genus Stromatoneurospora was erected in 1973 by Jong and Davis to accommodate the pyrophilic pyrenomycete Sphaeria phoenix and has traditionally been placed in the family Xylariaceae based on morphological features. However, no living culture of this genus has so far been available in the public domain. Molecular data were restricted to an internal transcribed spacer (ITS) sequence that only confirmed the familial position, and was generated from a strain that is not deposited in a public culture collection. We have recently collected fresh material and were able to culture this fungus from Thailand. The secondary metabolites of this strains were analysed after fermentation in multiple media. The the prominent components of these fermentation were purified, using preparative chromatography. Aside from two new eremophilane sesquiterpenoids named phoenixilanes A–B (1–2), four other components that are known from species of the xylariaceous genera Xylaria and Poronia were identified by spectral methods (nuclear magnetic resonance spectroscopy and high resolution mass spectrometry). Notably, (−)-(R)-6-hydroxy-3-methyl-4-dihydroisocoumarin-5-carboxylic acid (6) has not been reported as a natural product before. Moreover, DNA sequences of Stromatoneurospora phoenix clustered with members of the genera Poronia and Podosordaria in a multi-locus molecular phylogeny. These results confirmed that the genus belongs to the same evolutionary lineage as the coprophilic Xylariaceae. The results also suggest that this lineage has evolved independently from the plant-inhabiting saprotrophs and endophytes that are closely related to the genus Xylaria. These findings are discussed in relation to some theories about the endophytic vs. the pyrophilic/coprophilic fungal life style.

Contribution to the macromycetes of West Bengal, India: 51–56

Abstract: The West Bengal is a treasure house for macro-fungal diversity due to its varied geo-climatic conditions. Detailed macroscopic and microscopic characterization was made to identify the collected specimens. Altogether six species belonging to the family Xylariaceae (three species), Hypoxylaceae (one species), Ascobolaceae (one species) and Pyronemataceae (one species) were collected from different corners of the state. Literature survey revealed that all of the collected taxa represent their first detailed description and distributional record from the state. A comprehensive macro-morphological description, field photographs along with microscopic observations are provided. The outcome of the present study will enrich data related to the diversity of macrofungi from the state West Bengal.

Eremophilane sesquiterpenes from the mangrove fungus BCC 60405

Eight eremophilanolides (1, 2, 5–8, 10, and 12), 7-epi-tessaric acid (13), an eremophilane (14), and five known compounds, mairetolide F (3), 13-hydroxymairetolide F (4), 3α-hydroxymairetolide A (9), xylareremophil (11), and (3R,4R)-4-hydroxy-5-methylmellein (15), were isolated from the mangrove fungus BCC 60405 belonging to the family Xylariaceae. The structures of these compounds were elucidated by extensive spectroscopic analysis. The isolated compounds were evaluated for antimalarial, antibacterial, antituberculosis and cytotoxic activities. All compound were inactive except for compound 6 that showed weak cytotoxicity against Vero cells (African green monkey kidney fibroblast cells) with an IC50 of 49.6 μg/mL.

Viromes in Xylariaceae fungi infecting avocado in Spain

Four isolates of Entoleuca sp., family Xylariaceae, Ascomycota, recovered from avocado rhizosphere in Spain were analyzed for mycoviruses presence. For that, the dsRNAs from the mycelia were extracted and subjected to metagenomics analysis that revealed the presence of eleven viruses putatively belonging to families Partitiviridae, Hypoviridae, Megabirnaviridae, and orders Tymovirales and Bunyavirales, in addition to one ourmia-like virus plus other two unclassified virus species. Moreover, a sequence with 98% nucleotide identity to plant endornavirus Phaseolus vulgaris alphaendornavirus 1 has been identified in the Entoleuca sp. isolates. Concerning the virome composition, the four isolates only differed in the presence of the bunyavirus and the ourmia-like virus, while all other viruses showed common patterns. Specific primers allowed the detection by RT-PCR of these viruses in a collection of Entoleuca sp. and Rosellinia necatrix isolates obtained from roots of avocado trees. Results indicate that intra- and interspecies horizontal virus transmission occur frequently in this pathosystem.

DIVERSIDAD FÚNGICA EN LA ATMÓSFERA DE LA HABANA (CUBA) DURANTE TRES PERÍODOS POCO LLUVIOSOS

The climate of Havana favors a high representation of fungi in the air during the year, mainly in the day-time. In the periods of low rainfall (November to April), the greatest climatic variations are evident, which can affect the appearance of allergic and respiratory diseases. The objective of this work was to characterize the atmospheric diurnal mycobiota of Havana during three consecutive dry periods. Forty-eight viable volumetric samples were obtained using a slit biocolector (chirana aeroscope) during three periods of low rainfall (November/2012-April/2013, November/2013-April/2014 and November/2014-April/2015). The collected fungi were isolated and identified. Simultaneously, visual identification of spores was conducted on the preparations from a Hirst type sampler (Lanzoni VPPS 2000), on the same day and time as the viable samplings. Subsequently, the concentration, relative density and relative frequency of fungal propagules identified by both methods were calculated. The three evaluated periods were quantitatively and qualitatively similar. Thirtyt two genera were identified, three genera only by viable methodology, 17 by non-viable and 11 by both methodologies. Spores of the order Uredinales and of the family Xylariaceae were also identified by the non-viable method. The genera Cladosporium, Aspergillus, Penicillium, Fusarium and Curvularia highlighted by their abundance and relative frequency. The mycobiota detected in both periods was similar in diversity and concentration of genera. Mean temperature and mean relative humidity were correlated with atmospheric concentrations of fungal propagules. The data provided are useful for the prevention of allergies and respiratory diseases, with a high incidence in the Cuban population during winter and dry periods.

Arugosins O-Q, New Fungal Metabolites from the Fungus Xylariaceae sp. Isolated from Leaves of Lansium domesticum (Meliaceae)

A fungal endophyte which was identified as a hitherto undescribed member of the family Xylariaceae by sequencing of the ITS region was isolated from fresh and healthy leaves of Lansium domesticum collected on tropical peatland of West Kalimantan, Indonesia. Chromatographic separation of the ethyl acetate extract of the fungus resulted in the isolation of three new arugosin type metabolites, including arugosins O (1), P (2), and Q (3). The structures were determined by analysis of 1D and 2D NMR spectra and HRMS data, and by comparison with data from the literature. Biological activities of those compounds are also reported.

Terphenyl derivatives and drimane – Phathalide/isoindolinones from Hypoxylon fendleri BCC32408

The genus Hypoxylon, a member of the family Xylariaceae, has been known to produce significant secondary metabolites in terms of chemical diversity. Moreover, the compounds isolated can also be used as chemotaxonomic characters for differentiation among the two sections, which are sect. Annulata and sect. Hypoxylon. In our continuing chemical screening programme for novel compounds, the crude extracts of H. fendleri BCC32408 gave significant chemical profiles in HPLC analyses. Thus, the chemical investigation of these crude extracts was then carried out. The investigation led to the isolation of ten previously undescribed compounds including three terphenylquinones (fendleryls A – C), one terphenyl (fendleryl D), and six novel drimane – phthalide-type lactone/isoindolinones derivatives (fendlerinines A – F) along with seven known compounds (2-O-methylatromentin, rickenyl E, atromentin, rickenyls C – D, (+)-ramulosin, and O-hydroxyphenyl acetic acid). The chemical structures were determined on the basis of spectroscopic analyses, including 1D, 2D NMR and high-resolution mass spectrometry, as well as chemical transformations. In addition, these isolated compounds were assessed for antimicrobial activity including antimalarial (against Plasmodium falciparum, K-1 strain), antifungal (against Candida albicans), antibacterial (against Bacillus cereus) activities. Cytotoxicity against both cancerous (KB, MCF-7, NCI-H187) and non-cancerous (Vero) cells of these compounds were also evaluated.

Minutellins A – D, azaphilones from the stromata of Annulohypoxylon minutellum (Xylariaceae)

During the course of our screening for new metabolites with chemotaxonomic importance from stromata of fungi from the family Xylariaceae, we characterized several interesting metabolites in the fungus Annulohypoxylon minutellum. Extraction of the fruiting bodies and purification by preparative HPLC resulted in the isolation of five metabolites. The main compound was identified as the known metabolite hinnulin A (5), while four minor compounds were found to represent previously undescribed azaphilones, named minutellins A – D (1–4). Their planar structures were elucidated using NMR and HRESIMS data; absolute stereochemistry was assigned by CD data and Mosher's method. Compounds 1, 3 and 5 showed cytotoxic effects against murine and human cells. As the production of 1–5 is restricted to a group of closely related Annulohypoxylon species, they serve well as chemotaxonomic marker.

Anthostomelloides krabiensis gen. et sp. nov. (Xylariaceae) from Pandanus odorifer (Pandanaceae)

An Anthostomella-like taxon was obtained from Pandanus odorifer (Forssk.) Kuntze (Pandanaceae) collected in Krabi Province in Thailand. Morphological data plus phylogenetic analyses of combined ITS, LSU, RPB2, and β-tubulin sequence data clearly separate this Anthostomella-like taxon from other known genera in Xylariaceae. In this paper, we introduce this taxon as a new genus, Anthostomelloides, in the family Xylariaceae, with A. krabiensis as the type. A detailed morphological description, phylogenetic tree, photomicrographs of A. krabiensis, keys to Anthostomella-like genera, and a comparison of A. krabiensis with the morphologically similar taxa in Xylariaceae are provided.

Daldinia concentrica - New Distribution Record from North East India

Daldinia concentrica (Bolton) Ces.& De Not. (Mycobank No. MB#146158) is an inedible saprobic macro fungi commonly known as King Alfred's cake, cramp balls and coal fungus. It grows on dead and decaying wood. The fungus belongs to the family Xylariaceae, order Xylarials, class Sordarimycetes and phylum Ascomycota. It was found firmly attached on a fallen branch of Mallotus ferrugineus (Roxb.) Mull. Arg.

Charcoal Canker of Pear, Plum, and Quince Trees Caused by Biscogniauxia rosacearum sp. nov. in Southern Italy.

The genus Biscogniauxia is paraphyletic to members of the family Xylariaceae and includes at least 52 species to date that are mainly pathogens of dicotyledonous angiosperm trees. Most of these are forest trees, such as those in the genera Acacia, Acer, Alnus, Eucalyptus, Fraxinus, Populus, and Quercus, and other species of minor importance. Biscogniauxia spp. have been reported as endophytes or secondary invaders that attack only stressed plants. During a survey in rosaceous orchards in southern Italy, several charcoal cankers were observed and stroma samples were collected. A collection of 31 Biscogniauxia isolates was analyzed. Their phylogenetic relationships were determined through study of the internal transcribed spacer, β-tubulin, and actin gene sequences. Combining morphological, cultural, and molecular data, a new species of Biscogniauxia is described here as Biscogniauxia rosacearum. This new species was isolated for the first time from rosaceous hosts in Apulia. Pathogenicity tests showed that it causes symptoms on stems when artificially inoculated and produces stromata on the bark surface.