Barbara Schulz - Academia.edu (original) (raw)
Papers by Barbara Schulz
Records of Natural Products, 2009
From the whole plant of Klainedoxa gabonenses betulinic acid (1), lupeol (2), ß-sitosterol (3), β... more From the whole plant of Klainedoxa gabonenses betulinic acid (1), lupeol (2), ß-sitosterol (3), βamyran-3-one (4) and 3,3',4'-triO -methylellagic acid (5) were isolated. Similarly paullinomide A (6), β-amyrin (7), 2-(4-hydroxy-3,5-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-1,4,5-trioxaphenanthren-6-one (8), 5αporiferastane-3ß,6α-diol (9), β-sitosterol (3), l-quebrachitol (10), and ß-sitosterol glucopyranoside (11) were isolated from roots of Paullinia pinnata. Preliminary studies showed that 2-(4-hydroxy-3,5-dimethoxyphenyl)-3hydroxymethyl-2,3-dihydro-1,4,5-trioxaphenanthren-6-one (8) showed moderate algicidal activity against the alga Chlorella fusca
Records of Natural Products, 2009
Chemical and biological investigations of the endophytic fungus of an unidentified Ascomycete, is... more Chemical and biological investigations of the endophytic fungus of an unidentified Ascomycete, isolated from Meliotus dentatus led to the isolation of six known polyketide metabolites (1-6) and two steroids (7 and 8). Compounds 1-3, and 5 were tested for antibacterial, antialgal and antifungal activities. Compounds 2, 3, and 5 showed good activity against the alga Chlorella fusca, while compounds 2 and 3 were active against the Gram negative bacterium Escherichia coli and compounds 3 and 5 also against the Gram positive Bacillus megaterium. Similarly, compounds 3 and 5 also showed antifungal activity against Microbotryum violaceum.
The Journal of Antibiotics, 1994
Natural Product Communications, Oct 1, 2008
Three new pyrenocines, F (6), G (7), and H (8), along with the known pyrenocine A (1) were isolat... more Three new pyrenocines, F (6), G (7), and H (8), along with the known pyrenocine A (1) were isolated from the ethyl acetate extract of an unidentified endophytic fungus. Metabolites 1 and 7 exhibited good antifungal and algicidal activities.
Natural Product Communications, Nov 1, 2009
triol (9), were isolated from Colletotrichum sp., an endophytic fungus isolated from Ilex canarie... more triol (9), were isolated from Colletotrichum sp., an endophytic fungus isolated from Ilex canariensis from Gomera. The structures of these compounds were elucidated by detailed spectroscopic analysis, comparison with reported data, and chemical interconversion. The isolation of these metabolites not only displays a beautiful array of chemical diversity, but also gives insight into the biosynthetic interconnections. Preliminary studies showed antimicrobial activity of these compounds against the fungus Microbotryum violaceum, the alga Chlorella fusca, and the bacteria Escherichia coli and Bacillus megaterium.
Symbiosis, 2016
Die Erscheinung der Symbiose, meaning “the phenomenon of symbiosis” in English or “de la symbiose... more Die Erscheinung der Symbiose, meaning “the phenomenon of symbiosis” in English or “de la symbiose” in French, is a transcription of the 1878 lecture by the German botanist and mycologist Heinrich Anton de Bary in which he first used the term ‘symbiosis’ in a biological context. De Bary’s speech was published in 1879 in German, later to be translated into French; though only fragments of his speech are available in English. Translating de Bary’s lecture is timely because the field of symbiosis, especially with respect to microorganisms, is expanding and the importance of symbiosis is now recognized across the biological sciences. Researchers have now begun to sort through the early literature to uncover original thoughts pertaining to symbiotic interactions. We believe that having de Bary’s lecture accessible to researchers in English will help enhance interest in the history of symbioses, document de Bary’s pioneering contribution, and aid in establishing an understanding for whom the lecture was intended and when biological symbioses were first recognized. We present a short biography of Heinrich Anton de Bary, a full translation of his lecture, and conclude by briefly highlighting current endeavors in symbiosis research.
Biomolecules
A fungal endophyte originating from the Canary Islands was identified as a potent antagonist agai... more 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...
Journal of Plant Diseases and Protection
The invasive ascomycete Hymenoscyphus fraxineus is the causative agent for ash dieback on the Eur... more The invasive ascomycete Hymenoscyphus fraxineus is the causative agent for ash dieback on the European species Fraxinus excelsior and Fraxinus angustifolia, and there is concern that it is going to replace the native, closely related and nonpathogenic Hymenoscyphus albidus. Fungal management in forests is limited, and alternative approaches for control are needed. Within the scope of the project “FraxForFuture”, several strategies are being investigated. One idea comprises the use of a viral hyperparasite, which can induce a reduced virulence in the fungal host H. fraxineus in an antagonist-like system. This phenomenon, the reduction of fungal virulence by a viral infection, is known as hypovirulence, and a similar method has already been established to control the Chestnut Blight in Europe. We examined 34 isolates of H. fraxineus for both their virulence and presence of a viral infection. Although a predominant number of isolates were found to be infected with Hymenoscyphus mitovir...
Tetrahedron Letters, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Phytochemistry, Apr 1, 2014
a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus p... more a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus pseudoalbidus (2014) Phytochemistry, 100, pp. 86-91. Hymenosetin, a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus pseudoalbidus
Journal of Natural Products, Aug 14, 2009
Seven new drimane sesquiterpenoids (1-3, 6-9), along with the known compounds deoxyuvidin B (4), ... more Seven new drimane sesquiterpenoids (1-3, 6-9), along with the known compounds deoxyuvidin B (4), strobilactone B (5), and RES-1149-2 (10), were obtained from cultures of the fungus Aspergillus ustus, which was isolated from the marine sponge Suberites domuncula. Their structures were established by means of spectroscopic analyses including one- and two-dimensional NMR spectroscopy and high-resolution MS. Compounds 6, 7, and 10 showed cytotoxic activity against a panel of tumor cell lines, including L5178Y, HeLa, and PC12 cells, with 7 being the most active (EC(50) against L5178Y cell line: 0.6 microg/mL).
Botanica Marina, Mar 7, 2008
Specimens of Suberites domuncula that had been cultured in aquaria for 4 weeks were analyzed for ... more Specimens of Suberites domuncula that had been cultured in aquaria for 4 weeks were analyzed for their associated fungi. A total of 81 fungal strains belonging to 20 different genera was isolated and identified by morphological and molecular methods. The most frequently isolated taxa were Cladosporium spp., Penicillium spp., Petriella sp., Phialophora spp. and Engyodontium album. Based on chromatographic and mass spectrometric analysis of fungal extracts, as well as on bioassay results, Aspergillus ustus, Penicillium sp., Petriella sp. and Scopulariopsis sp. were selected for in-depth analysis of their natural products. A total of 19 different fungal metabolites, including three new natural products, was isolated and structurally identified. A. ustus yielded two sesquiterpenes, a drimane derivative and deoxyuvidin, as well as a sesterterpene ophiobolin H. The drimane derivative had an ED 50 value against L5178Y cells of 1.9 mg ml-1 in vitro. The crude extract of Petriella sp. was also strongly cytotoxic against the L5178Y cell line. The cyclic tetrapeptide WF-3161 was primarily responsible for the activity; the ED 50 value was-0.1 mg ml-1. It was identical to the known compound WF-3161 and had been previously isolated from Petriella guttulata. In addition to WF-3161, three further natural products were obtained and unequivocally identified as new derivatives of infectopyrone by one-and two-dimensional NMR spectroscopy and by
Fungal Biology and Biotechnology
Background Due to the infection with the invasive ascomycete Hymenoscyphus fraxineus, which has b... more 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 reporte...
SummaryPhytophthora infestans (Phy. infestans) is a devastating pathogen of tomato and potato. It... more SummaryPhytophthora infestans (Phy. infestans) is a devastating pathogen of tomato and potato. It readily overcomes resistance genes and applied agrochemicals. Fungal endophytes provide a largely unexplored avenue of control against Phy. infestans. Not only do endophytes produce a wide array of bioactive metabolites, they may also directly compete with and defeat pathogens in planta.Twelve isolates of fungal endophytes from different plant species were tested in vitro for their production of metabolites with anti-Phy. infestans activity. Four well-performing isolates were evaluated for their ability to suppress nine isolates of Phy. infestans on agar medium and in planta.Two endophytes reliably inhibited all Phy. infestans isolates on agar medium, of which Phoma eupatorii isolate 8082 was the most promising. It nearly abolished infection by Phy. infestans in planta.Here we present a biocontrol agent, which can inhibit a broad-spectrum of Phy. infestans isolates. Such broadly acting ...
Fungal Ecology, 2020
Our goal is to develop a biocontrol agent using endophytic fungi to control ash dieback, a diseas... more Our goal is to develop a biocontrol agent using endophytic fungi to control ash dieback, a disease that endangers the very existence of the European ash, Fraxinus excelsior. Such a protective endophyte should produce metabolites toxic to the invasive fungus Hymenoscyphus fraxineus, the causal agent of ash dieback. From a total of 340 fungal endophytes from F. excelsior, the interactions with 13 exemplary isolates are presented here. In co-culture between H. fraxineus and endophyte, there was almost always reciprocal inhibition between pathogen and endophyte. Endophytes that inhibited H. fraxineus more than they were inhibited by the pathogen were inoculated into axenically cultured F. excelsior to select those that grew asymptomatically in the host. Most of the endophytes caused disease symptoms in axenically cultured F. excelsior seedlings, highlighting the importance of not only relying on co-culture experiments, but also using in planta experiments. By means of a multi-locus genealogy in conjunction with morphological studies and a comparison with the ex-epitype culture, one of the most promising isolates was identified as Hypoxylon rubiginosum, an ascomycete fungus that is closely associated with Fraxinus and frequently produces its sexual morph on dead wood of the host. Using preparative HPLC, metabolites were isolated from mono-and co-cultures of H. fraxineus and H. rubiginosum and their structures elucidated by NMR spectroscopy and HR mass spectrometry. The known phytotoxin viridiol was detected as a major metabolite of the ash pathogen in co-culture and the previously known antifungal metabolite, phomopsidin, as the major secondary metabolite of H. rubiginosum. In addition, the new metabolite, 10hydroxyphomopsidin, was obtained from H. rubiginosum. Phomopsidin, a known inhibitor of betatubulin that targets the eukaryotic cytoskeleton, inhibited the pathogen, but also showed mild cytotoxic effects. The fact that H. rubiginosum grows asymptomatically in planta and that it produces the antifungal metabolite phomopsidin qualifies it as a promising candidate for further development as a biocontrol agent for ash dieback.
Sustainable Development and Biodiversity, 2019
Compounds isolated from different natural sources have over the years played crucial roles in the... more Compounds isolated from different natural sources have over the years played crucial roles in the treatment of a wide range of human diseases. Over the past six decades, microorganisms have provided valuable active compounds for the treatment of various diseases. Fungi, in general, produce diverse structural classes of natural products including polyketides, a major class of secondary metabolites obtained from various natural sources‚ which as a group have interesting chemical diversity. In addition, polyketides are known to possess a number of biological and pharmacological effects, viz. cytotoxic, antibacterial, antifungal, antiparasitic, and immunosuppressive effects. In this chapter the focus is on describing the cytotoxic effects of polyketides isolated from fungi and in particular their potential as cancerostatic pharmaceuticals.
Soil Biology, 2006
The use of general descriptive names, registered names, trademarks, etc. in this publication does... more The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Records of Natural Products, 2009
From the whole plant of Klainedoxa gabonenses betulinic acid (1), lupeol (2), ß-sitosterol (3), β... more From the whole plant of Klainedoxa gabonenses betulinic acid (1), lupeol (2), ß-sitosterol (3), βamyran-3-one (4) and 3,3',4'-triO -methylellagic acid (5) were isolated. Similarly paullinomide A (6), β-amyrin (7), 2-(4-hydroxy-3,5-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-1,4,5-trioxaphenanthren-6-one (8), 5αporiferastane-3ß,6α-diol (9), β-sitosterol (3), l-quebrachitol (10), and ß-sitosterol glucopyranoside (11) were isolated from roots of Paullinia pinnata. Preliminary studies showed that 2-(4-hydroxy-3,5-dimethoxyphenyl)-3hydroxymethyl-2,3-dihydro-1,4,5-trioxaphenanthren-6-one (8) showed moderate algicidal activity against the alga Chlorella fusca
Records of Natural Products, 2009
Chemical and biological investigations of the endophytic fungus of an unidentified Ascomycete, is... more Chemical and biological investigations of the endophytic fungus of an unidentified Ascomycete, isolated from Meliotus dentatus led to the isolation of six known polyketide metabolites (1-6) and two steroids (7 and 8). Compounds 1-3, and 5 were tested for antibacterial, antialgal and antifungal activities. Compounds 2, 3, and 5 showed good activity against the alga Chlorella fusca, while compounds 2 and 3 were active against the Gram negative bacterium Escherichia coli and compounds 3 and 5 also against the Gram positive Bacillus megaterium. Similarly, compounds 3 and 5 also showed antifungal activity against Microbotryum violaceum.
The Journal of Antibiotics, 1994
Natural Product Communications, Oct 1, 2008
Three new pyrenocines, F (6), G (7), and H (8), along with the known pyrenocine A (1) were isolat... more Three new pyrenocines, F (6), G (7), and H (8), along with the known pyrenocine A (1) were isolated from the ethyl acetate extract of an unidentified endophytic fungus. Metabolites 1 and 7 exhibited good antifungal and algicidal activities.
Natural Product Communications, Nov 1, 2009
triol (9), were isolated from Colletotrichum sp., an endophytic fungus isolated from Ilex canarie... more triol (9), were isolated from Colletotrichum sp., an endophytic fungus isolated from Ilex canariensis from Gomera. The structures of these compounds were elucidated by detailed spectroscopic analysis, comparison with reported data, and chemical interconversion. The isolation of these metabolites not only displays a beautiful array of chemical diversity, but also gives insight into the biosynthetic interconnections. Preliminary studies showed antimicrobial activity of these compounds against the fungus Microbotryum violaceum, the alga Chlorella fusca, and the bacteria Escherichia coli and Bacillus megaterium.
Symbiosis, 2016
Die Erscheinung der Symbiose, meaning “the phenomenon of symbiosis” in English or “de la symbiose... more Die Erscheinung der Symbiose, meaning “the phenomenon of symbiosis” in English or “de la symbiose” in French, is a transcription of the 1878 lecture by the German botanist and mycologist Heinrich Anton de Bary in which he first used the term ‘symbiosis’ in a biological context. De Bary’s speech was published in 1879 in German, later to be translated into French; though only fragments of his speech are available in English. Translating de Bary’s lecture is timely because the field of symbiosis, especially with respect to microorganisms, is expanding and the importance of symbiosis is now recognized across the biological sciences. Researchers have now begun to sort through the early literature to uncover original thoughts pertaining to symbiotic interactions. We believe that having de Bary’s lecture accessible to researchers in English will help enhance interest in the history of symbioses, document de Bary’s pioneering contribution, and aid in establishing an understanding for whom the lecture was intended and when biological symbioses were first recognized. We present a short biography of Heinrich Anton de Bary, a full translation of his lecture, and conclude by briefly highlighting current endeavors in symbiosis research.
Biomolecules
A fungal endophyte originating from the Canary Islands was identified as a potent antagonist agai... more 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...
Journal of Plant Diseases and Protection
The invasive ascomycete Hymenoscyphus fraxineus is the causative agent for ash dieback on the Eur... more The invasive ascomycete Hymenoscyphus fraxineus is the causative agent for ash dieback on the European species Fraxinus excelsior and Fraxinus angustifolia, and there is concern that it is going to replace the native, closely related and nonpathogenic Hymenoscyphus albidus. Fungal management in forests is limited, and alternative approaches for control are needed. Within the scope of the project “FraxForFuture”, several strategies are being investigated. One idea comprises the use of a viral hyperparasite, which can induce a reduced virulence in the fungal host H. fraxineus in an antagonist-like system. This phenomenon, the reduction of fungal virulence by a viral infection, is known as hypovirulence, and a similar method has already been established to control the Chestnut Blight in Europe. We examined 34 isolates of H. fraxineus for both their virulence and presence of a viral infection. Although a predominant number of isolates were found to be infected with Hymenoscyphus mitovir...
Tetrahedron Letters, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Phytochemistry, Apr 1, 2014
a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus p... more a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus pseudoalbidus (2014) Phytochemistry, 100, pp. 86-91. Hymenosetin, a 3-decalinoyltetramic acid antibiotic from cultures of the ash dieback pathogen, Hymenoscyphus pseudoalbidus
Journal of Natural Products, Aug 14, 2009
Seven new drimane sesquiterpenoids (1-3, 6-9), along with the known compounds deoxyuvidin B (4), ... more Seven new drimane sesquiterpenoids (1-3, 6-9), along with the known compounds deoxyuvidin B (4), strobilactone B (5), and RES-1149-2 (10), were obtained from cultures of the fungus Aspergillus ustus, which was isolated from the marine sponge Suberites domuncula. Their structures were established by means of spectroscopic analyses including one- and two-dimensional NMR spectroscopy and high-resolution MS. Compounds 6, 7, and 10 showed cytotoxic activity against a panel of tumor cell lines, including L5178Y, HeLa, and PC12 cells, with 7 being the most active (EC(50) against L5178Y cell line: 0.6 microg/mL).
Botanica Marina, Mar 7, 2008
Specimens of Suberites domuncula that had been cultured in aquaria for 4 weeks were analyzed for ... more Specimens of Suberites domuncula that had been cultured in aquaria for 4 weeks were analyzed for their associated fungi. A total of 81 fungal strains belonging to 20 different genera was isolated and identified by morphological and molecular methods. The most frequently isolated taxa were Cladosporium spp., Penicillium spp., Petriella sp., Phialophora spp. and Engyodontium album. Based on chromatographic and mass spectrometric analysis of fungal extracts, as well as on bioassay results, Aspergillus ustus, Penicillium sp., Petriella sp. and Scopulariopsis sp. were selected for in-depth analysis of their natural products. A total of 19 different fungal metabolites, including three new natural products, was isolated and structurally identified. A. ustus yielded two sesquiterpenes, a drimane derivative and deoxyuvidin, as well as a sesterterpene ophiobolin H. The drimane derivative had an ED 50 value against L5178Y cells of 1.9 mg ml-1 in vitro. The crude extract of Petriella sp. was also strongly cytotoxic against the L5178Y cell line. The cyclic tetrapeptide WF-3161 was primarily responsible for the activity; the ED 50 value was-0.1 mg ml-1. It was identical to the known compound WF-3161 and had been previously isolated from Petriella guttulata. In addition to WF-3161, three further natural products were obtained and unequivocally identified as new derivatives of infectopyrone by one-and two-dimensional NMR spectroscopy and by
Fungal Biology and Biotechnology
Background Due to the infection with the invasive ascomycete Hymenoscyphus fraxineus, which has b... more 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 reporte...
SummaryPhytophthora infestans (Phy. infestans) is a devastating pathogen of tomato and potato. It... more SummaryPhytophthora infestans (Phy. infestans) is a devastating pathogen of tomato and potato. It readily overcomes resistance genes and applied agrochemicals. Fungal endophytes provide a largely unexplored avenue of control against Phy. infestans. Not only do endophytes produce a wide array of bioactive metabolites, they may also directly compete with and defeat pathogens in planta.Twelve isolates of fungal endophytes from different plant species were tested in vitro for their production of metabolites with anti-Phy. infestans activity. Four well-performing isolates were evaluated for their ability to suppress nine isolates of Phy. infestans on agar medium and in planta.Two endophytes reliably inhibited all Phy. infestans isolates on agar medium, of which Phoma eupatorii isolate 8082 was the most promising. It nearly abolished infection by Phy. infestans in planta.Here we present a biocontrol agent, which can inhibit a broad-spectrum of Phy. infestans isolates. Such broadly acting ...
Fungal Ecology, 2020
Our goal is to develop a biocontrol agent using endophytic fungi to control ash dieback, a diseas... more Our goal is to develop a biocontrol agent using endophytic fungi to control ash dieback, a disease that endangers the very existence of the European ash, Fraxinus excelsior. Such a protective endophyte should produce metabolites toxic to the invasive fungus Hymenoscyphus fraxineus, the causal agent of ash dieback. From a total of 340 fungal endophytes from F. excelsior, the interactions with 13 exemplary isolates are presented here. In co-culture between H. fraxineus and endophyte, there was almost always reciprocal inhibition between pathogen and endophyte. Endophytes that inhibited H. fraxineus more than they were inhibited by the pathogen were inoculated into axenically cultured F. excelsior to select those that grew asymptomatically in the host. Most of the endophytes caused disease symptoms in axenically cultured F. excelsior seedlings, highlighting the importance of not only relying on co-culture experiments, but also using in planta experiments. By means of a multi-locus genealogy in conjunction with morphological studies and a comparison with the ex-epitype culture, one of the most promising isolates was identified as Hypoxylon rubiginosum, an ascomycete fungus that is closely associated with Fraxinus and frequently produces its sexual morph on dead wood of the host. Using preparative HPLC, metabolites were isolated from mono-and co-cultures of H. fraxineus and H. rubiginosum and their structures elucidated by NMR spectroscopy and HR mass spectrometry. The known phytotoxin viridiol was detected as a major metabolite of the ash pathogen in co-culture and the previously known antifungal metabolite, phomopsidin, as the major secondary metabolite of H. rubiginosum. In addition, the new metabolite, 10hydroxyphomopsidin, was obtained from H. rubiginosum. Phomopsidin, a known inhibitor of betatubulin that targets the eukaryotic cytoskeleton, inhibited the pathogen, but also showed mild cytotoxic effects. The fact that H. rubiginosum grows asymptomatically in planta and that it produces the antifungal metabolite phomopsidin qualifies it as a promising candidate for further development as a biocontrol agent for ash dieback.
Sustainable Development and Biodiversity, 2019
Compounds isolated from different natural sources have over the years played crucial roles in the... more Compounds isolated from different natural sources have over the years played crucial roles in the treatment of a wide range of human diseases. Over the past six decades, microorganisms have provided valuable active compounds for the treatment of various diseases. Fungi, in general, produce diverse structural classes of natural products including polyketides, a major class of secondary metabolites obtained from various natural sources‚ which as a group have interesting chemical diversity. In addition, polyketides are known to possess a number of biological and pharmacological effects, viz. cytotoxic, antibacterial, antifungal, antiparasitic, and immunosuppressive effects. In this chapter the focus is on describing the cytotoxic effects of polyketides isolated from fungi and in particular their potential as cancerostatic pharmaceuticals.
Soil Biology, 2006
The use of general descriptive names, registered names, trademarks, etc. in this publication does... more The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.