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Seven new isoprenyl phenolic ethers, namely fimbriethers A‒G (1‒7), were isolated from the fermented broth of the termite nest-derived medicinal fungus Xylaria fimbriata YMJ491. Their structures were determined by spectroscopic data analysis and compared with those reported. The effects of all the isolates at a concentration of 100 μM on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells were evaluated, and all of them exhibited NO production inhibitory activity with E max values ranging from 4.6 ± 2.0% to 49.7 ± 0.5% without significant cytotoxicity. In addition, these seven compounds did not alter phenylephrine-induced vasocontraction in isolated intact thoracic aortic rings from C57BL/6J mouse, indicating 1‒7 were not involved in the regulation of endothelial NOS-mediated NO production., (Copyright © 2018. Published by Elsevier Taiwan LLC.)

Three new sesquiterpene acids, xylaric acids A-C (1-3, resp.), and a new tetralone (=3,4-dihydronaphthalen-1(2H)-one) derivative, 4, along with nine known compounds, xylaric acid D (5), hydroheptelidic acid (6), gliocladic acid (7), chlorine heptelidic acid (8), trichoderonic acid A (9), 16-(α-D-mannopyranosyloxy)isopimar-7-en-19-oic acid (10), 16-(α-D-glucopyranosyloxy)isopimar-7-en-19-oic acid (11), 5-carboxymellein (12), and naphthalen-1,8-diol 1-O-α-D-glucopyranoside (13) have been isolated from the solid culture of the ascomycete fungus Xylaria sp. associated with termite nest. The structures of these compounds were elucidated primarily by NMR experiments. The absolute configurations of compounds 1-3 and 5-9 were determined by combination of X-ray data and CD spectral analysis. The absolute configuration of 4 was assigned by Snatzke's method. Compounds 8 and 11 showed slight cytotoxicities against two cell lines A549 and SGC7901., (2011 Verlag Helvetica Chimica Acta AG, Zürich.)

Studies have revealed that some Xylaria species were closely associated with fungus-growing termite nests. However this relationship rarely had been investigated and the host specificity of termite-associated Xylaria was not yet clearly established. Eighteen Xylaria rDNA-ITS sequences were obtained from fungus combs belonging to 11 Macrotermitinae species from eight regions. Low diversity was found between isolates, and nine sequences were retrieved. Termite-associated Xylaria were shown to be monophyletic, with three main clades, all including strains from various termite hosts and geographical localities. This new molecular study shows no species specificity with respect to fungus-growing termites, which suggests that there might be substrate specialization.

Fungus-growing termites live in obligate mutualistic symbiosis with species of the basidiomycete genus Termitomyces, which are cultivated on a substrate of dead plant material. When the termite colony dies, or when nest material is incubated without termites in the laboratory, fruiting bodies of the ascomycete genus Xylaria appear and rapidly cover the fungus garden. This raises the question whether certain Xylaria species are specialised in occupying termite nests or whether they are just occasional visitors. We tested Xylaria specificity at four levels: (1) fungus-growing termites, (2) termite genera, (3) termite species, and (4) colonies. In South Africa, 108 colonies of eight termite species from three termite genera were sampled for Xylaria. Xylaria was isolated from 69% of the sampled nests and from 57% of the incubated fungus comb samples, confirming high prevalence. Phylogenetic analysis of the ITS region revealed 16 operational taxonomic units of Xylaria, indicating high levels of Xylaria species richness. Not much of this variation was explained by termite genus, species, or colony; thus, at level 2-4 the specificity is low. Analysis of the large subunit rDNA region, showed that all termite-associated Xylaria belong to a single clade, together with only three of the 26 non-termite-associated strains. Termite-associated Xylaria thus show specificity for fungus-growing termites (level 1). We did not find evidence for geographic or temporal structuring in these Xylaria phylogenies. Based on our results, we conclude that termite-associated Xylaria are specific for fungus-growing termites, without having specificity for lower taxonomic levels.

Nine species of Xylaria were collected in Taiwan from nests of Odontotermes formosanus, the only known macrotermitine termite in Taiwan. These include six newly described species, X. acuminatilongissima, X. atrodivaricata, X. brunneovinosa, X. griseosepiacea, X. intraflava and X. ochraceostroma, and three previously known species, X. cirrata, X. escharoidea and X. nigripes. We obtained cultures and ITS sequences from the nine species found in Taiwan and describe anamorphs for eight of them. Before the current study teleomorph-anamorph connections in the Xylaria species associated with termite nests have been established unequivocally in X. escharoidea only. Xylaria angulosa, X. fimbriata, X. kedahae, X. micrura, X. radicans, X. reinkingii and X. tolosa also are considered and annotated because they were reported to grow on ground and likely are associated with termite nests. Epitypifications are made for X. cirrata, X. escharoidea and X. nigripes. Xylaria sanchezii is considered a nomen dubium. Photographs are presented for most of the aforementioned species. A dichotomous key to 25 Xylaria species growing on termite nests or ground also is given.

Xylaria arenicola, X. brasiliensis, X. escharoidea, X. furcata, X. nigripes, X. piperiformis and X. rhizomorpha represent ancient names of fungi known to inhabit abandoned termite nests. We attempt to redescribe them and to reduce the confusion among them. Xylaria tanganyikaensis and X. readeri, species that might be associated with termite nests, are described. We describe a new variety, X. furcata var. hirsuta, and discuss an unnamed fungus that probably represents a new species. Photographs and a key are presented to aid the identification of these taxa.