Covering: up to December 2017 The diversity of secondary metabolites in the fungal order Xylariales is reviewed with special emphasis on correlations between chemical diversity and biodiversity as ...inferred from recent taxonomic and phylogenetic studies. The Xylariales are arguably among the predominant fungal endophytes, which are the producer organisms of pharmaceutical lead compounds including the antimycotic sordarins and the antiparasitic nodulisporic acids, as well as the marketed drug, emodepside. Many Xylariales are "macromycetes", which form conspicuous fruiting bodies (stromata), and the metabolite profiles that are predominant in the stromata are often complementary to those encountered in corresponding mycelial cultures of a given species. Secondary metabolite profiles have recently been proven highly informative as additional parameters to support classical morphology and molecular phylogenetic approaches in order to reconstruct evolutionary relationships among these fungi. Even the recent taxonomic rearrangement of the Xylariales has been relying on such approaches, since certain groups of metabolites seem to have significance at the species, genus or family level, respectively, while others are only produced in certain taxa and their production is highly dependent on the culture conditions. The vast metabolic diversity that may be encountered in a single species or strain is illustrated based on examples like Daldinia eschscholtzii, Hypoxylon rickii, and Pestalotiopsis fici. In the future, it appears feasible to increase our knowledge of secondary metabolite diversity by embarking on certain genera that have so far been neglected, as well as by studying the volatile secondary metabolites more intensively. Methods of bioinformatics, phylogenomics and transcriptomics, which have been developed to study other fungi, are readily available for use in such scenarios.
The Basidiomycota constitutes the second largest higher taxonomic group of the Fungi after the Ascomycota and comprises over 30.000 species. Mycelial cultures of Basidiomycota have already been ...studied since the 1950s for production of antibiotics and other beneficial secondary metabolites. Despite the fact that unique and selective compounds like pleuromutilin were obtained early on, it took several decades more until they were subjected to a systematic screening for antimicrobial and anticancer activities. These efforts led to the discovery of the strobilurins and several hundreds of further compounds that mainly constitute terpenoids. In parallel the traditional medicinal mushrooms of Asia were also studied intensively for metabolite production, aimed at finding new therapeutic agents for treatment of various diseases including metabolic disorders and the central nervous system. While the evaluation of this organism group has in general been more tedious as compared to the Ascomycota, the chances to discover new metabolites and to develop them further to candidates for drugs, agrochemicals and other products for the Life Science industry have substantially increased over the past decade. This is owing to the revolutionary developments in –OMICS techniques, bioinformatics, analytical chemistry and biotechnological process technology, which are steadily being developed further. On the other hand, the new developments in polythetic fungal taxonomy now also allow a more concise selection of previously untapped organisms. The current review is dedicated to summarize the state of the art and to give an outlook to further developments.
•The literature on biologically active secondary metabolites from Basidiomycota is reviewed and some highlights are presented•Selected examples of developmental candidates for pharmaceutial and agrochemical applications are discussed•The state of the art on biosynthesis and biotechnological production of metabolites from Basidiomycota is also discussed
The cosmopolitan plant genus
Clematis
contains many climbing species that can be found worldwide. The genus occurs in the wild and is grown commercially for horticulture. Microfungi on
Clematis
were ...collected from Belgium, China, Italy, Thailand and the UK. They are characterized by morphology and analyses of gene sequence data using an integrated species concept to validate identifications. The study revealed two new families, 12 new genera, 50 new species, 26 new host records with one dimorphic character report, and ten species are transferred to other genera. The new families revealed by multigene phylogeny are Longiostiolaceae and Pseudomassarinaceae in Pleosporales (Dothideomycetes). New genera are
Anthodidymella
(Didymellaceae),
Anthosulcatispora
and
Parasulcatispora
(Sulcatisporaceae),
Fusiformispora
(Amniculicolaceae),
Longispora
(Phaeosphaeriaceae),
Neobyssosphaeria
(Melanommataceae),
Neoleptosporella
(
Chaetosphaeriales
, genera
incertae sedis)
,
Neostictis
(Stictidaceae),
Pseudohelminthosporium
(Neomassarinaceae),
Pseudomassarina
(Pseudomassarinaceae),
Sclerenchymomyces
(Leptosphaeriaceae) and
Xenoplectosphaerella
(Plectosphaerellaceae). The newly described species are
Alloleptosphaeria clematidis
,
Anthodidymella ranunculacearum
,
Anthosulcatispora subglobosa
,
Aquadictyospora clematidis
,
Brunneofusispora clematidis
,
Chaetosphaeronema clematidicola
,
C. clematidis
,
Chromolaenicola clematidis
,
Diaporthe clematidina
,
Dictyocheirospora clematidis
,
Distoseptispora clematidis
,
Floricola clematidis
,
Fusiformispora clematidis
,
Hermatomyces clematidis
,
Leptospora clematidis
,
Longispora clematidis
,
Massariosphaeria clematidis
,
Melomastia clematidis
,
M. fulvicomae
,
Neobyssosphaeria clematidis
,
Neoleptosporella clematidis
,
Neoroussoella clematidis
,
N. fulvicomae
,
Neostictis nigricans, Neovaginatispora clematidis
,
Parasulcatispora clematidis
,
Parathyridaria clematidis, P. serratifoliae
,
P. virginianae
,
Periconia verrucose
,
Phomatospora uniseriata
,
Pleopunctum clematidis
,
Pseudocapulatispora clematidis
,
Pseudocoleophoma clematidis
,
Pseudohelminthosporium clematidis
,
Pseudolophiostoma chiangraiense
,
P. clematidis
,
Pseudomassarina clematidis
,
Ramusculicola clematidis
,
Sarocladium clematidis
,
Sclerenchymomyces clematidis
,
Sigarispora clematidicola
,
S. clematidis
,
S. montanae
,
Sordaria clematidis
,
Stemphylium clematidis
,
Wojnowiciella clematidis
,
Xenodidymella clematidis
,
Xenomassariosphaeria clematidis
and
Xenoplectosphaerella clematidis.
The following fungi are recorded on
Clematis
species for the first time:
Angustimassarina rosarum
,
Dendryphion europaeum
,
Dermatiopleospora mariae
,
Diaporthe ravennica
,
D. rudis
,
Dichotomopilus ramosissimum
,
Dictyocheirospora xishuangbannaensis
,
Didymosphaeria rubi
-
ulmifolii
,
Fitzroyomyces cyperacearum
,
Fusarium celtidicola
,
Leptospora thailandica
,
Memnoniella oblongispora
,
Neodidymelliopsis longicolla
,
Neoeutypella baoshanensis
,
Neoroussoella heveae
,
Nigrograna chromolaenae
,
N. obliqua
,
Pestalotiopsis verruculosa
,
Pseudoberkleasmium chiangmaiense
,
Pseudoophiobolus rosae
,
Pseudoroussoella chromolaenae
,
P. elaeicola
,
Ramusculicola thailandica
,
Stemphylium vesicarium
and
Torula chromolaenae
. The new combinations are
Anthodidymella clematidis
(≡
Didymella clematidis
),
A. vitalbina
(≡
Didymella vitalbina
),
Anthosulcatispora brunnea
(≡
Neobambusicola brunnea
),
Fuscohypha kunmingensis
(≡
Plectosphaerella kunmingensis
),
Magnibotryascoma rubriostiolata
(≡
Teichospora rubriostiolata
),
Pararoussoella mangrovei
(≡
Roussoella mangrovei
),
Pseudoneoconiothyrium euonymi
(≡
Roussoella euonymi
),
Sclerenchymomyces jonesii
(≡
Neoleptosphaeria jonesii
),
Stemphylium rosae
(≡
Pleospora rosae)
, and
S. rosae
-
caninae
(≡
Pleospora rosae
-
caninae
). The microfungi on
Clematis
is distributed in several classes of Ascomycota. The analyses are based on morphological examination of specimens, coupled with phylogenetic sequence data. To the best of our knowledge, the consolidated species concept approach is recommended in validating species.
Molecular phylogenetic studies of cultures derived from some specimens of plant-inhabiting Sordariomycetes using ITS, LSU,
rpb2
and
tub2
DNA sequence data revealed close affinities to strains of
...Muscodor
. The taxonomy of this biotechnologically important genus, which exclusively consists of endophytes with sterile mycelia that produce antibiotic volatile secondary metabolites, was based on a rather tentative taxonomic concept. Even though it was accommodated in Xylariaceae, its phylogenetic position had so far remained obscure. Our phylogeny shows that
Muscodor
species have affinities to the xylarialean genera
Emarcea
and
Induratia
, which is corroborated by the fact that their sexual states produce characteristic apiospores. These data allow for the integration of
Muscodor
in
Induratia
, i.e. the genus that was historically described first. The multi-locus phylogenetic tree clearly revealed that a clade comprising
Emarcea
and
Induratia
forms a monophylum separate from representatives of Xylariaceae, for which we propose the new family Induratiaceae. Divergence time estimations revealed that Induratiaceae has been diverged from the Xylariaceae + Clypeosphaeriaceae clade at 93 (69–119) million years ago (Mya) with the crown age of 61 (39–85) Mya during the Cretaceous period. The ascospore-derived cultures were studied for the production of volatile metabolites, using both, dual cultures for assessment of antimicrobial effects and extensive analyses using gas chromatography coupled with mass spectrometry (GC–MS). The antimicrobial effects observed were significant, but not as strong as in the case of the previous reports on
Muscodor
species. The GC–MS results give rise to some doubt on the validity of the previous identification of certain volatiles. Many peaks in the GC–MS chromatograms could not be safely identified by database searches and may represent new natural products. The isolation of these compounds by preparative chromatography and their subsequent characterisation by nuclear magnetic resonance (NMR) spectroscopy or total synthesis will allow for a more concise identification of these volatiles, and they should also be checked for their individual contribution to the observed antibiotic effects. This will be an important prerequisite for the development of biocontrol strains.
4-Hydroxypleurogrisein, a congener of the anticancer-lead compound pleurotin, as well as six further derivatives were isolated from the basidiomycete
, strain MFLUCC 12-0451. The structures were ...elucidated utilizing high resolution electron spray ionization mass spectrometry (HRESIMS) and 1D and 2D nuclear magnetic resonance (NMR) spectral data and evaluated for their biological activities; for leucopleurotin, we provide Xray data. While most congeners showed moderate antimicrobial and cytotoxic activity, 4-hydroxypleurogrisein emerged as an inhibitor of hepatitis C virus infectivity in mammalian liver cells.
Two novel pyridino-cyathane diterpenoids, pyristriatins A and B (1 and 2), together with striatin C (3) were isolated from cultures of Cyathus cf. striatus, a basidiomycete that was found during a ...field trip in northern Thailand. The pyristriatins showed antimicrobial effects against Gram-positive bacteria and fungi. The isolation, structure elucidation, relative configuration, and biological and cytotoxic activity are described. Their structures were assigned by HRMS and NMR spectroscopy. We also describe the first 2D NMR assignment of striatin C. Pyristriatins A and B are the first cyathane natural products featuring a pyridine ring.
Morphological characters and multi-gene phylogenetic analyses were used to identify Retiboletus specimens collected in northern Thailand. Retiboletus brevibasidiatus is described as new to science, ...whereas R. fuscus and R. nigrogriseus are reported for the first time from Thailand. Retiboletus brevibasidiatus produces medium-sized basidiomes, with a dark blonde to clay pileus and densely reticulate stipe mostly on the upper part with pale yellow to chrome yellow basal mycelium. It is difficult to separate R. brevibasidiatus from other closely related species on the basis of macroscopic characters. However, the new species can be distinguished by microscopic characters, mostly the shorter basidia. The macro- and micro-morphology of the R. fuscus and R. nigrogriseus collections from Thailand fit well with the previous descriptions of materials from China and Japan. Detailed descriptions, molecular phylogeny, and illustrations of the three species are provided.
A recent find of a
Marasmius
species in Northern Thailand led to the isolation of five unprecedented derivatives of the carotane antibiotic fulvoferruginin (
1
), fulvoferruginins B–F (
2
–
6
). The ...structures of these sesquiterpenoids were elucidated using HRESIMS, 1D and 2D NMR, as well as CD spectroscopy. Assessing the bioactivity, fulvoferruginin emerged as a potent cytotoxic agent of potential pharmaceutical interest.
Bioassay-guided fractionation of antibacterial extracts from cultures of a basidiomycete from Northern Thailand, which represents a new species of the genus Deconica, yielded the terpenoid deconin A ...(1), whose structure was elucidated by spectral methods (NMR, HRMS) as a cuparenic/mevalonic acid conjugate. The absolute configuration of 1 was determined after saponification and comparison of specific rotations of the resulting cuparenic acid and mevalonolactone with authentic standards and literature data. Six minor congeners (2–7) were isolated and identified, and their antimicrobial and cytotoxic effects are reported. Compounds 1–4 are the first natural products featuring an unmodified mevalonic acid residue as a building block.
Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this ...taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal "death caps" and "destroying angels". Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii.
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