Strong antagonism of an endophyte of Fraxinus excelsior towards the ash dieback pathogen, Hymenoscyphus fraxineus, is mediated by the antifungal secondary metabolite PF1140.

Ash dieback, caused by the fungal pathogen Hymenoscyphus fraxineus (Helotiales, Ascomycota), is threatening the existence of the European ash, Fraxineus excelsior. During our search for biological control agents for this devastating disease, endophytic fungi were isolated from healthy plant tissues and co-cultivated with H. fraxineus to assess their antagonistic potential. Among the strains screened, Penicillium cf. manginii DSM 104493 most strongly inhibited the pathogen. Initially, DSM 104493 showed promise in planta as a biocontrol agent. Inoculation of DSM 104493 into axenically cultured ash seedlings greatly decreased the development of disease symptoms in seedlings infected with H. fraxineus. The fungus was thus cultivated on a larger scale in order to obtain sufficient material to identify active metabolites that accounted for the antibiosis observed in dual culture. We isolated PF1140 (1) and identified it as the main active compound in the course of a bioassay-guided isolation strategy. Furthermore, its derivative 2, the mycotoxin citreoviridin (3), three tetramic acids of the vancouverone type (4-6), and penidiamide (7) were isolated by preparative chromatography. The structures were elucidated mainly by NMR spectroscopy and high-resolution mass spectrometry (HRMS), of which compounds 2 and 6 represent novel natural products. Of the compounds tested, not only PF1140 (1) strongly inhibited H. fraxineus in an agar diffusion assay but also showed phytotoxic effects in a leaf puncture assay. Unfortunately, both the latent virulent attributes of DSM 104493 observed subsequent to these experiments in planta and the production of mycotoxins exclude strain Penicillium cf. manginii DSM 104493 from further development as a safe biocontrol agent.IMPORTANCEEnvironmentally friendly measures are urgently needed to control the causative agent of ash dieback, Hymenoscyphus fraxineus. Herein, we show that the endophyte DSM 104493 exhibits protective effects in vitro and in planta. We traced the activity of DSM 104493 to the antifungal natural product PF1140, which unfortunately also showed phytotoxic effects. Our results have important implications for understanding plant-fungal interactions mediated by secondary metabolites, not only in the context of ash dieback but also generally in plant-microbial interactions.

Magnetic resonance imaging characteristics in patients with psoriatic arthritis and axial manifestations from the MAXIMISE cohort.

OBJECTIVE: The current analysis of the MAXIMISE trial was conducted to investigate the presence of post-inflammatory and degenerative spinal changes and inflammatory changes in spinal processes identified in baseline MRIs and their potential for predicting differential treatment effects in a cohort of PsA patients with axial manifestations. METHODS: Baseline spinal MRIs from the MAXIMISE trial were re-read to identify additional inflammatory (spinal process), post-inflammatory, and degenerative changes, and investigate the differential treatment effect of these imaging features using logistic regression modelling. RESULTS: In addition to bone marrow oedema assessed at primary analysis, spinal process inflammation and post-inflammatory changes evaluated by FAt Spondyloarthritis Spine Score were documented in 11.1% and 20.2% patients, respectively. At least one type of degenerative change was noted in 64% patients, with Pfirrmann grade ≥3 (51.1%) being the most common. Combining primary and re-read MRI findings, 67.1% of patients presented with inflammatory or post-inflammatory changes while 21.2% had degenerative changes alone. Although not statistically significant, post-inflammatory changes were associated with a trend for better efficacy outcomes in terms of ASAS20, ASAS40 and BASDAI50 responses; a trend for worse outcomes was observed in the presence of degenerative changes. CONCLUSION: The current analysis revealed the occurrence of additional inflammatory and post-inflammatory changes suggestive of axial PsA (axPsA) and a trend for better clinical outcomes for patients treated with secukinumab. These results elucidate the imaging characteristics and improve our current understanding of axPsA thereby supporting the interpretation of future trials. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02721966.

Secukinumab in patients with psoriatic arthritis and axial manifestations: results from the double-blind, randomised, phase 3 MAXIMISE trial.

OBJECTIVES: MAXIMISE (Managing AXIal Manifestations in psorIatic arthritis with SEcukinumab) trial was designed to evaluate the efficacy of secukinumab in the management of axial manifestations of psoriatic arthritis (PsA). METHODS: This phase 3b, double-blind, placebo-controlled, multi-centre 52-week trial included patients (≥18 years) diagnosed with PsA and classified by ClASsification criteria for Psoriatic Arthritis (CASPAR) criteria, with spinal pain Visual Analogue Score ≥40/100 and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥4 despite use of at least two non-steroidal anti-inflammatory drugs (NSAIDs). Patients were randomised (1:1:1) to secukinumab 300 mg, secukinumab 150 mg or placebo weekly for 4 weeks and every 4 weeks thereafter. At week 12, placebo patients were re-randomised to secukinumab 300/150 mg. Primary endpoint was ASAS20 (Assessment of SpondyloArthritis international Society) response with secukinumab 300 mg at week 12. RESULTS: Patients were randomly assigned; 167 to secukinumab 300 mg, 165 to secukinumab 150 mg and 166 to placebo. Secukinumab 300 mg and 150 mg significantly improved ASAS20 response versus placebo at week 12 (63% and 66% vs 31% placebo). The OR (95% CI) comparing secukinumab 300 mg and 150 mg versus placebo, using a logistic regression model after multiple imputation, was 3.8 (2.4 and 6.1) and 4.4 (2.7 and 7.0; p<0.0001). CONCLUSIONS: Secukinumab 300 mg and 150 mg provided significant improvement in signs and symptoms of axial disease compared with placebo in patients with PsA and axial manifestations with inadequate response to NSAIDs. TRIAL REGISTRATION NUMBER: NCT02721966.

Microsphaerol and seimatorone: two new compounds isolated from the endophytic fungi, Microsphaeropsis sp. and Seimatosporium sp.

A new polychlorinated triphenyl diether named microsphaerol (1), has been isolated from the endophtic fungus Microsphaeropsis sp. An intensive phytochemical investigation of the endophytic fungus Seimatosporium sp., led to the isolation of a new naphthalene derivative named seimatorone (2) and eight known compounds, i.e., 1-(2,6-dihydroxyphenyl)-3-hydroxybutan-1-one (3), 1-(2,6-dihydroxyphenyl)butan-1-one (4), 1-(2-hydroxy-6-methoxyphenyl)butan-1-one (5), 5-hydroxy-2-methyl-4H-chromen-4-one (6), 2,3-dihydro-5-hydroxy-2-methyl-4H-chromen-4-one (7), 8-methoxynaphthalen-1-ol (8), nodulisporins A and B (9 and 10, resp.), and daldinol (11). The structures of 1 and 2 were elucidated by detailed spectroscopic analysis including (1) H- and (13) C-NMR, COSY, HMQC, HMBC, and HR-EI-MS, while the structures of the known compounds were deduced from comparison of their spectral data with those in the literature. Preliminary studies revealed that microsphaerol (1) showed good antibacterial activities against B. Megaterium and E. coli, and good antilagal and antifungal activities against C. fusca, M. violaceum, respectively. On the other hand, seimatorone (2) exhibited moderate antibacterial, antialgal, and antifungal activities.

Seimisochromenes A and B: two new dihydroisochromenes from the endophytic fungus, Seimatosporium sp.

Two new dihydroisochromenes, named seimisochromenes A and B (1 and 2), were isolated from an endophytic fungus, Seimatosporium sp. The structures of seimisochromenes A and B have been determined from 1D ((1)H and (13)C NMR spectra) and 2D (COSY, HMQC, HMBC, and NOESY) NMR experiments.

Microdiplanol and microdiplane: a new m-anisaldehyde and a new 24-methylcholestanol derivative from the endophytic fungus Microdiplodia sp.

Phytochemical investigation of the endophytic fungus Microdiplodia sp. afforded a new m-anisaldehyde derivative named microdiplanol (1) and a new 24-methylcholestanol derivative named microdiplane (2). Their structures were confirmed by a comprehensive analysis of 1D and 2D NMR and mass spectrometric data.

Pogostol biosynthesis by the endophytic fungus Geniculosporium.

Six (13)C-labelled isotopomers of mevalonolactone were synthesised and used in feeding experiments with the endophytic fungus Geniculosporium. The high incorporation rates of (13)C-label into a sesquiterpene that was found in headspace extracts of the fungus enabled unambiguous identification of this volatile as pogostol without the need for compound purification, simply by collecting the volatile fraction with a closed-loop stripping apparatus followed by direct (13)C NMR analysis (CLSA-NMR). The feeding experiments also gave insights into the biosynthesis of pogostol, including stereochemical aspects of the terpene cyclisation reaction. The possible biological function of pogostol is discussed.

α-Glucosidase and lipoxygenase inhibitory derivatives of cryptosporioptide from the endophytic fungus Cryptosporiopsis sp.

Two new cryptosporioptide-derived polyketides cryptosporioptides A (2) and B (3) were isolated from the extract of endophytic fungus Cryptosporiopsis sp. associated with the shrub, Viburnum tinus. The structures of the isolates were determined through spectral analysis including 1D NMR ((1)H, (13)C) and 2D NMR (HSQC, HMBC, COSY) techniques, HR-FAB-MS and by comparison with the reported data of cryptosporioptide (1). The relative stereochemistry was assigned with the help of NOESY analysis, the molecular model, and comparison of the optical rotation values with the reference compound 1.

Coniothyren: a new phenoxyphenyl ether from the endophytic fungus, Coniothyrium sp.

Phytochemical investigation of the endophytic fungus Coniothyrium sp. resulted in the isolation of a new phenoxyphenyl ether, named coniothyren (1), and two known compounds, coniol (2) and (+)-epoxydon (3). The structure of the new compound was elucidated by detailed spectroscopic analysis, namely, (1)H NMR, (13)C NMR, COSY, HMQC, HMBC, and HR-EI-MS. Preliminary studies demonstrated that (+)-epoxydon (3) displayed good antibacterial and antialgal activities toward Bacillus megaterium and Chlorella fusca, respectively.

A volatile lactone of Hymenoscyphus pseudoalbidus, pathogen of European ash dieback, inhibits host germination.

The largely unknown secondary metabolism of the plant pathogenic fungus Hymenoscyphus pseudoalbidus was investigated by use of the CLSA method. A set of volatile lactones was identified by GC/MS. The lactones were synthesized and used in bioassays in which one of the compounds was found to be a strong germination inhibitor for ash seeds, causing necroses in the plant tissue.

Structure, absolute configuration, and conformational study of 12-membered macrolides from the fungus Dendrodochium sp. associated with the sea cucumber Holothuria nobilis Selenka.

Dendrodolides A-M (1-13), 13 new 12-membered macrolides, were isolated from Dendrodochium sp., a fungus associated with the sea cucumber Holothuria nobilis Selenka, which was collected from the South China Sea. The structures of the dendrodolides were elucidated by means of detailed spectroscopic analysis and X-ray single-crystal diffraction. The absolute configurations were assigned using the modified Mosher method, exciton-coupled circular dichroism (ECCD), electronic solution and solid-state circular dichroism (ECD) supported by time-dependent density functional theory (TDDFT) ECD calculations, and X-ray analysis. A detailed conformational analysis of the 13 derivatives indicated that the conformation of the flexible macrolide ring plays a decisive role in their chiroptical properties. Thus, it is highly recommended to apply advanced levels of theory and to avoid simple comparison of ECD spectra to determine the absolute configurations of these derivatives. In an in vitro bioassay, compounds 1-5, 7-9, 11, and 12 exhibited different levels of growth inhibitory activity against SMMC-7721 and HCT116 cells. This is the first report of 12-membered macrolides from the fungus of the genus Dendrodochium . The coisolation of four pairs of epimers is extremely interesting and indicates the complexity of ß-ketoreductase stereospecificity in the biosynthesis of enigmatic iterative fungal polyketides.

Structural and stereochemical studies of hydroxyanthraquinone derivatives from the endophytic fungus Coniothyrium sp.

Four known hydroxyanthraquinones (1-4) together with four new derivatives having a tetralone moiety, namely coniothyrinones A-D (5-8), were isolated from the culture of Coniothyrium sp., an endophytic fungus isolated from Salsola oppostifolia from Gomera in the Canary Islands. The structures of the new compounds were elucidated by detailed spectroscopic analysis and comparison with reported data. The absolute configurations of coniothyrinones A (5), B (6), and D (8) were determined by TDDFT calculations of CD spectra, allowing the determination of the absolute configuration of coniothyrinone C (7) as well. Coniothyrinones A (5), B (6), and D (8) could be used as ECD reference compounds in the determination of absolute configuration for related tetralone derivatives. This is the first report of anthraquinones and derivatives from an isolate of the genus Coniothyrium sp. These compounds showed inhibitory effects against the fungus Microbotryum violaceum, the alga Chlorella fusca, and the bacteria Escherichia coli and Bacillus megaterium.

Stable overexpression and targeted gene deletion of the causative agent of ash dieback Hymenoscyphus fraxineus.

BACKGROUND: Due to the infection with the invasive ascomycete Hymenoscyphus fraxineus, which has been replacing the closely related and non-pathogenic native Hymenoscyphus albidus, the European ashes, Fraxinus excelsior (also known as the common ash), Fraxinus angustifolia (also known as narrow-leaved ash) and Fraxinus ornus (also known as the manna ash) are at risk. Hymenoscyphus fraxineus is the causative agent of ash dieback of the European ashes, but is non-pathogenic to the native Asian ash Fraxinus mandshurica (also known as the Manchurian ash). Even though the invasion of H. fraxineus is a great threat for ashes in Europe, the fungal biology is still poorly understood. By the use of live cell imaging and targeted gene knock-out, the fungal life cycle and host-pathogen interaction can be studied in more detail. RESULTS: Here, we developed a protocol for the preparation of protoplasts from mycelium of H. fraxineus, for their regeneration and for stable transformation with reporter genes and targeted gene knock-out by homologous recombination. We obtained mutants with various levels of reporter gene expression which did not correlate with the number of integrations. In an in vitro infection assay, we demonstrated the suitability of reporter gene overexpression for fungal detection in plant tissue after inoculation. As a proof of principle for targeted gene knock-out, the hygromycin resistance cassette of a reporter gene-expressing mutant was replaced with a geneticin resistance cassette. CONCLUSIONS: The invasive fungal pathogen H. fraxineus is threatening the European ashes. To develop strategies for pest management, a better understanding of the fungal life cycle and its host interaction is crucial. Here, we provide a protocol for stable transformation of H. fraxineus to obtain fluorescence reporter strains and targeted gene knock-out mutants. This protocol will help future investigations on the biology of this pathogen.

Bioactive Compounds from an Endophytic Pezicula sp. Showing Antagonistic Effects against the Ash Dieback Pathogen.

A fungal endophyte originating from the Canary Islands was identified as a potent antagonist against the fungal phytopathogen Hymenoscyphus fraxineus, which causes the devastating ash dieback disease. This endophyte was tentatively identified as Pezicula cf. ericae, using molecular barcoding. Isolation of secondary metabolites by preparative high-performance liquid chromatography (HPLC) yielded the known compounds CJ-17,572 (1), mycorrhizin A (3) and cryptosporioptides A-C (4-6), besides a new N-acetylated dihydroxyphenylalanin derivative 2, named peziculastatin. Planar structures were elucidated by NMR and HRMS data, while the relative stereochemistry of 2 was assigned by H,H and C,H coupling constants. The assignment of the unknown stereochemistry of CJ-17,572 (1) was hampered by the broadening of NMR signals. Nevertheless, after semisynthetic conversion of 1 into its methyl derivatives 7 and 8, presumably preventing tautomeric effects, the relative configuration could be assigned, whereas comparison of ECD data to those of related compounds determined the absolute configuration. Metabolites 1 and 3 showed significant antifungal effects in vitro against H. fraxineus. Furthermore, 4-6 exhibited significant dispersive effects on preformed biofilms of S. aureus at concentrations up to 2 µg/mL, while the biofilm formation of C. albicans was also inhibited. Thus, cryptosporioptides might constitute a potential source for the development of novel antibiofilm agents.

Herbarone, a rearranged heptaketide derivative from the sea hare associated fungus Torula herbarum.

Herbarone (1), a novel heptaketide with a tetrahydro-5,9-methanobenzo[8]annulen-10(5H)-one skeleton, together with the new ent-astropaquinones B (2) and C (3) and four known pyranonaphthoquinones (4-7), was isolated from the sea hare associated fungus Torula herbarum. The structures of the new compounds were elucidated by detailed spectroscopic analysis, and the absolute configurations were determined by solution TDDFT/ECD calculations. Absolute configurations of the known compounds were studied by ECD measurements and calculations. The isolation of heptaketide 1 suggests that an intramolecular aldol reaction takes place to form the tricyclic scaffold.

Algicidal lactones from the marine Roseobacter clade bacterium Ruegeria pomeroyi.

Volatiles released by the marine Roseobacter clade bacterium Rugeria pomeroyi were collected by use of a closed-loop stripping headspace apparatus (CLSA) and analysed by GC-MS. Several lactones were found for which structural proposals were derived from their mass spectra and unambiguously verified by the synthesis of reference compounds. An enantioselective synthesis of two exemplary lactones was performed to establish the enantiomeric compositions of the natural products by enantioselective GC-MS analyses. The lactones were subjected to biotests to investigate their activity against several bacteria, fungi, and algae. A specific algicidal activity was observed that may be important in the interaction between the bacteria and their algal hosts in fading algal blooms.

Predictors of response to secukinumab in patients with psoriatic arthritis and axial manifestations: a post-hoc analysis of the MAXIMISE trial.

OBJECTIVES: To investigate patient characteristics predictive of response to secukinumab in patients with psoriatic arthritis (PsA) with axial manifestations. METHODS: In a post-hoc analysis from the MAXIMISE trial (NCT02721966) in patients with PsA and axial manifestations, we tested the hypothesis that the OR of the effect of treatment on the primary endpoint of the trial (Assessment of SpondyloArthritis international Society (ASAS) 20 responder status at week 12) would be different depending on 12 prespecified predictor variables. We applied a two-model logistic regression approach, a main effects and an interaction model. RESULTS: The OR (95% CI) for ASAS20 response for the presence of nail dystrophy was 3.2 (95% CI 0.93 to 10.99) in the secukinumab 150 mg group and 5.0 (95% CI 1.47 to 17.19) in the secukinumab 300 mg group compared with the placebo group (p=0.029). Odds of being a responder were similar in men and women in the secukinumab groups, though men fared worse than women in the placebo group (p=0.039). Current smokers were less likely to be ASAS20 responders compared with never smokers regardless of the treatment group (p=0.589). CONCLUSION: Nail dystrophy was identified as a predictor of response to secukinumab in patients with PsA with axial manifestations in the MAXIMISE trial. These findings may be explained by the nail-entheseal concept as part of the axial phenotype in PsA .

Interim 2-Year Analysis from SERENA: A Real-World Study in Patients with Psoriatic Arthritis or Ankylosing Spondylitis Treated with Secukinumab.

INTRODUCTION: Sustained improvement of high degree in clinical outcomes have been demonstrated in phase 3 trials with secukinumab in both psoriatic arthritis (PsA) and ankylosing spondylitis (AS). The objective of the SERENA study was to evaluate the effectiveness, retention rates, and safety of secukinumab in patients with PsA and AS. METHODS: SERENA is an ongoing, longitudinal, real-world observational study involving patients with moderate-to-severe psoriasis, PsA, or AS. Patients had received at least 16 weeks of secukinumab treatment before recruitment to the study. Retention rate was defined as percentage of patients who continued secukinumab treatment over the course of study. Effectiveness of secukinumab in AS and PsA cohorts was assessed using descriptive statistics. RESULTS: The current interim analysis included 1004 patients with PsA or AS. Overall secukinumab retention rates at 2 years after enrolment were 74.9 and 78.9% in patients with PsA and AS, respectively. At baseline and at 2 years, swollen joint count [3.3 (5.8) vs. 2.9 (5.8)], tender joint count [6.3 (9.4) vs. 5.6 (7.2)] in patients with PsA and BASDAI scores [3.2 (2.3) vs. 2.9 (2.3)] in patients with AS, suggest sustained effectiveness for patients remaining on secukinumab for at least 2 years after enrolment. A total of 73 patients had treatment interruption; 78% of these patients reinitiated secukinumab without a loading dose. No new or unexpected safety signals were reported. CONCLUSIONS: After more than 2 years since initiation, secukinumab demonstrated high retention rates and favorable safety profile as well as sustained effectiveness in patients who continued secukinumab treatment.

Bioactive nonanolide derivatives isolated from the endophytic fungus Cytospora sp.

Cytospolides F-Q (6-17) and decytospolides A and B (18 and 19), 14 unusual nonanolide derivatives, were isolated from Cytospora sp., an endophytic fungus from Ilex canariensis. The structures were elucidated by means of detailed spectroscopic analysis, chemical interconversion, and X-ray single crystal diffraction. The solution- and solid-state conformers were compared by the combination of experimental methods (X-ray, NMR) supported by DFT calculations of the conformers. Absolute configurations were assigned using the modified Mosher's method and solution- and solid-state TDDFT ECD calculations. In an in vitro cytotoxicity assay toward the tumor cell lines of A549, HCT116, QGY, A375, and U973, the γ-lactone 17 demonstrated a potent growth inhibitory activity toward the cell line A-549, while nonanolide 16 with (2S) configuration showed the strongest activity against cell lines A-549, QGY, and U973. A cell cycle analysis indicated that compound 16 can significantly mediate G1 arrest in A549 tumor cells, confirming the important role of the C-2 methyl in the growth inhibition toward the tumor line. The discovery of an array of new nonanolides demonstrates the productivity of the fungus, and it is an example of chemical diversity, extending the nonanolide family by derivatives formed by ring cleavage, oxidation, esterification, and Michael addition.