• Taxonomic analyses of members of the Streptomyces cinnabarinus cluster, description of Streptomyces cinnabarigriseus sp. nov. and Streptomyces davaonensis sp. nov.

      Landwehr, Wiebke; Kämpfer, Peter; Glaeser, Stefanie P; Rückert, Christian; Kalinowski, Jörn; Blom, Jochen; Goesmann, Alexander; Mack, Matthias; Schumann, Peter; Atasayar, Ewelina; et al. (2017-12-11)
      Roseoflavin is the only known riboflavin (vitamin B2) analog with antibiotic properties. It is actively taken up by many micro-organisms and targets flavinmononucleotide riboswitches and flavoproteins. It is described as the product of the tentatively named 'Streptomyces davawensis' JCM 4913. Taxonomic analysis of this strain with a polyphasic approach showed that it is very closely related to Streptomyces cinnabarinus (DSM 40467). The two Streptomyces isolates were obtained from different geographical locations (the Philippines and the Kamchatka Peninsula, respectively), their genomes have been sequenced and the question was whether or not the two isolates were representatives of the same species. As we also worked with another isolate of Streptomyces cinnabarinus JS 360, the producer of the cinnabaramides, we wanted to clarify the taxonomic position of the three isolates by using a polyphasic approach. After analysis of the 16S rRNA gene sequence, we found in total 23 species of the genus Streptomyces that showed a similarity higher than 98.5 % to the three strains. We showed that 'S. davawensis' JCM 4913 and S. cinnabarinus DSM 40467 were very closely related but belong to two different species. Hence, we validate 'S. davawensis' as Streptomyces davaonensis sp. nov. with the type strain JCM 4913T (=DSM 101723T). In addition, the cinnabaramide producer can be clearly differentiated from S. davaonensis and this isolate is described as Streptomyces cinnabarigriseus sp. nov. with strain JS360T (=NCCB 100590T=DSM 101724T) as the type strain.
    • Taxonomic utility of old names in current fungal classification and nomenclature: Conflicts, confusion & clarifications

      Dayarathne, MC; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016)
    • Taxonomy, Diversity and Cultivation of the Oudemansielloid/Xeruloid Taxa Hymenopellis, Mucidula, Oudemansiella, and Xerula and with Respect to Their Bioactivities: A Review.

      Niego, Allen Grace; Raspé, Olivier; Thongklang, Naritsada; Charoensup, Rawiwan; Lumyong, Saisamorn; Stadler, Marc; Hyde, Kevin D; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2021-01-13)
      The oudemansielloid/xeruloid taxa Hymenopellis, Mucidula, Oudemansiella, and Xerula are genera of Basidiomycota that constitute an important resource of bioactive compounds. Numerous studies have shown antimicrobial, anti-oxidative, anti-cancer, anti-inflammatory and other bioactivities of their extracts. The bioactive principles can be divided into two major groups: (a) hydrophilic polysaccharides with relatively high molecular weights and (b) low molecular medium polar secondary metabolites, such as the antifungal strobilurins. In this review, we summarize the state of the art on biodiversity, cultivation of the fungi and bioactivities of their secondary metabolites and discuss future applications. Although the strobilurins are well-documented, with commercial applications as agrochemical fungicides, there are also other known compounds from this group that have not yet been well-studied. Polysaccharides, dihydro-citrinone phenol A acid, scalusamides, and acetylenic lactones such as xerulin, also have potential applications in the nutraceutical, pharmaceutical and medicinal market and should be further explored. Further studies are recommended to isolate high quality bioactive compounds and fully understand their modes of action. Given that only few species of oudemansielloid/xeruloid mushrooms have been explored for their production of secondary metabolites, these taxa represent unexplored sources of potentially useful and novel bioactive metabolites.
    • Ten reasons why a sequence-based nomenclature is not useful for fungi anytime soon.

      Thines, Marco; Crous, Pedro W; Aime, M Catherine; Aoki, Takayuki; Cai, Lei; Hyde, Kevin D; Miller, Andrew N; Zhang, Ning; Stadler, Marc; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (BMC, 2018-05-28)
      The large number of species still to be discovered in fungi, together with an exponentially growing number of environmental sequences that cannot be linked to known taxa, has fuelled the idea that it might be necessary to formally name fungi on the basis of sequence data only. Here we object to this idea due to several shortcomings of the approach, ranging from concerns regarding reproducibility and the violation of general scientific principles to ethical issues. We come to the conclusion that sequence-based nomenclature is potentially harmful for mycology as a discipline. Additionally, a classification based on sequences as types is not within reach anytime soon, because there is a lack of consensus regarding common standards due to the fast pace at which sequencing technologies develop.
    • Tetrasubstituted α-pyrone derivatives from the endophytic fungus, Neurospora udagawae

      Macabeo, Allan Patrick G.; Cruz, Allaine Jean C.; Narmani, Abolfazl; Arzanlou, Mahdi; Babai-Ahari, Asadollah; Pilapil, Luis Agustin E.; Garcia, Katherine Yasmin M.; Huch, Volker; Stadler, Marc; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Elsevier BV, 2020-02)
      Two new -pyrone derivatives, udagawanones A (1) and B (2), along with the known compounds (Z)-4-hydroxy-3-(3-hydroxy-3-methylbut-1-en-1-yl)benzoic acid (3), isosclerone (4), cyclo-(L-Leu-L-Pro) (5), and cyclo-(L-Pro-L-Tyr) (6), were isolated from cultures of the endophyte Neurospora udagawae. Their structures were elucidated by extensive spectroscopic methods and single crystal X-ray diffraction. Both compounds feature oxidized functionalities at the C-2 position not previously observed in other tetrasubstituted -pyrones from fungi. Compound 1 exhibited moderate antibacterial (vs. Staphylococcus aureus) and antifungal (vs. Rhodoturula glutinis) activities and cytotoxicity against KB3.1 cells.
    • Three New Derivatives of Zopfinol from Pseudorhypophila Mangenotii gen. et comb. nov

      Harms, Karen; Milic, Andrea; Stchigel, Alberto M; Stadler, Marc; Surup, Frank; Marin-Felix, Yasmina; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2021-03-03)
      Triangularia mangenotti was analyzed for the production of secondary metabolites, resulting in the isolation of known zopfinol (1) and its new derivatives zopfinol B-C (2-4), the 10-membered lactones 7-O-acetylmultiplolide A (5) and 8-O-acetylmultiplolide A (6), together with sordarin (7), sordarin B (8), and hypoxysordarin (9). The absolute configuration of 1 was elucidated by the synthesis of MPTA-esters. Compound 1 showed antimicrobial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus and the fungus Mucor hiemalis. While 4 was weakly antibacterial, 3 showed stronger antibiotic activity against the Gram-positive bacteria and weak antifungal activity against M. hiemalis and Rhodotorula glutinis. We furthermore observed the cytotoxicity of 1, 3 and 4 against the mammalian cell lines KB3.1 and L929. Moreover, the new genus Pseudorhypophila is introduced herein to accommodate Triangularia mangenotii together with several species of Zopfiella-Z. marina, Z. pilifera, and Z. submersa. These taxa formed a well-supported monophyletic clade in the recently introduced family Navicularisporaceae, located far from the type species of the respective original genera, in a phylogram based on the combined dataset sequences of the internal transcribed spacer region (ITS), the nuclear rDNA large subunit (LSU), and fragments of the ribosomal polymerase II subunit 2 (rpb2) and β-tubulin (tub2) genes. Zopfiella submersa is synonymized with P. marina due to the phylogenetic and morphological similarity. The isolation of zopfinols 1-4 and sordarins 7-9 confirms the potential of this fungal order as producers of bioactive compounds and suggests these compounds as potential chemotaxonomic markers.
    • Three new species of Hypoxylon and new records of Xylariales from Panama

      Cedeño–Sanchez, M; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Mushroom Research Foundation, 2020-03-31)
      This is a continuation of the papers “Towards a classification of Sordariomycetes” (2015) and “Families of Sordariomycetes” (2016) in which we compile a treatment of the class Sordariomycetes. The present treatment is needed as our knowledge has rapidly increased, from 32 orders, 105 families and 1331 genera in 2016, to 45 orders, 167 families and 1499 genera (with 308 genera incertae sedis) at the time of publication. In this treatment we provide notes on each order, families and short notes on each genus. We provide up-to-date DNA based phylogenies for 45 orders and 163 families. Three new genera and 16 new species are introduced with illustrations and descriptions, while 23 new records and three new species combinations are provided. We also list 308 taxa in Sordariomycetes genera incertae sedis. For each family we provide general descriptions and illustrate the type genus or another genus, the latter where the placement has generally been confirmed with molecular data. Both the sexual and asexual morphs representative of a family are illustrated where available. Notes on ecological and economic considerations are also given
    • Three novel species and a new record of Daldinia (Hypoxylaceae) from Thailand

      Wongkanoun, Sarunyou; Becker, Kevin; Boonmee, Kanthawut; Srikitikulchai, Prasert; Boonyuen, Nattawut; Chainuwong, Boonchuai; Luangsa-ard, Jennifer; Stadler, Marc; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Springer Science and Business Media LLC, 2020-10-08)
      n an investigation of stromatic Xylariales in Thailand, several specimens of Daldinia were discovered. Three novel species (D. flavogranulata, D. phadaengensis, and D. chiangdaoensis) were recognized from a molecular phylogeny based on concatenated ITS, LSU, RPB2, and TUB2 sequence data, combined with morphological characters and secondary metabolite profiles based on high performance liquid chromatography coupled to diode array detection and mass spectrometry (HPLC-MS). The major components detected were cytochalasins (in D. flavogranulata and D. chiangdaoensis) and daldinin type azaphilones (in D. phadaengensis). In addition, D. brachysperma, which had hitherto only been reported from America, was found for the first time in Asia. Its phylogenetic affinities were studied, confirming previous suspicions from morphological comparisons that the species is closely related to D. eschscholtzii and D. bambusicola, both common in Thailand. Daldinia flavogranulata, one of the new taxa, was found to be closely related to the same taxa. The other two novel species, D. phadaengensis and D. chiangdaoensis, share characters with D. korfii and D. kretzschmarioides, respectively.
    • Total Synthesis of Thuggacin cmc-A and Its Structure Determination.

      Tsutsumi, Tomohiro; Matsumoto, Moe; Iwasaki, Hitomi; Tomisawa, Kei; Komine, Keita; Fukuda, Hayato; Eustache, Jacques; Jansen, Rolf; Hatakeyama, Susumi; Ishihara, Jun; et al. (American Chemical Society, 2021-06-15)
      The first total synthesis of thuggacin cmc-A and the determination of the absolute structure are described. The thuggacin family of antibiotics is of great interest due to the antibiotic activity against Mycobacterium tuberculosis. Based on the assumption that seven stereogenic centers in thuggacin cmc-A would share the same stereochemistry as thuggacin-A, all stereogenic centers of thuggacin cmc-A were strictly constructed in a stereocontrolled manner. The total synthesis allowed its stereostructure to be fully confirmed.
    • Tutuilamides A-C: Vinyl-Chloride-Containing Cyclodepsipeptides from Marine Cyanobacteria with Potent Elastase Inhibitory Properties.

      Keller, Lena; Canuto, Kirley Marques; Liu, Chenxi; Suzuki, Brian M; Almaliti, Jehad; Sikandar, Asfandyar; Naman, C Benjamin; Glukhov, Evgenia; Luo, Danmeng; Duggan, Brendan M; et al. (AmericanChemical Society(ACS), 2020-01-28)
      Marine cyanobacteria (blue-green algae) have been shown to possess an enormous capacity to produce structurally diverse natural products that exhibit a broad spectrum of potent biological activities, including cytotoxic, antifungal, antiparasitic, antiviral, and antibacterial activities. Using mass-spectrometry-guided fractionation together with molecular networking, cyanobacterial field collections from American Samoa and Palmyra Atoll yielded three new cyclic peptides, tutuilamides A-C. Their structures were established by spectroscopic techniques including 1D and 2D NMR, HR-MS, and chemical derivatization. Structure elucidation was facilitated by employing advanced NMR techniques including nonuniform sampling in combination with the 1,1-ADEQUATE experiment. These cyclic peptides are characterized by the presence of several unusual residues including 3-amino-6-hydroxy-2-piperidone and 2-amino-2-butenoic acid, together with a novel vinyl chloride-containing residue. Tutuilamides A-C show potent elastase inhibitory activity together with moderate potency in H-460 lung cancer cell cytotoxicity assays. The binding mode to elastase was analyzed by X-ray crystallography revealing a reversible binding mode similar to the natural product lyngbyastatin 7. The presence of an additional hydrogen bond with the amino acid backbone of the flexible side chain of tutuilamide A, compared to lyngbyastatin 7, facilitates its stabilization in the elastase binding pocket and possibly explains its enhanced inhibitory potency.
    • Two cytotoxic triterpenes from cultures of a Kenyan Laetiporus sp. (Basidiomycota)

      Chepkirui, Clara; Matasyoh, Josphat, C.; Decock, Cony, A.; Stadler, Marc; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Elsevier, 2017-04-26)
      HPLC profiling of the mycelial culture of a poroid basidomycete collected in Mount Elgon, Kenya, which probably represents a new species of the genus Laetiporus, led to isolation of two previously undescribed lanostane type triterpenes.We propose the trivial names laetiporins A (1) and B (2). In addition, five known ones: dehydrosulphurenic acid (3), sulphurenic acid (4), eburicoic acid (5), 15α-hydroxytrametenolic acid (6) and trametenolic acid (7) were also isolated. The laetiporins (1–2) exhibited significant cytotoxic effects against various human cancer cells. The known compounds (3–5) and (7) also showed moderate cytotoxic activity, but none of the compounds showed any significant antimicrobial activity.
    • Two New Cyathane Diterpenoids from Mycelial Cultures of the Medicinal Mushroom Hericium erinaceus and the Rare Species, Hericium flagellum.

      Rupcic, Zeljka; Rascher, Monique; Kanaki, Sae; Köster, Reinhard W; Stadler, Marc; Wittstein, Kathrin; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-03-06)
      Basidiomycetes of the genusHericiumare among the most praised medicinal and edible mushrooms, which are known to produce secondary metabolites with the potential to treat neurodegenerative diseases. This activity has been attributed to the discovery of various terpenoids that can stimulate the production of nerve growth factor (NGF) or (as established more recently) brain-derived neurotrophic factor (BDNF) in cell-based bioassays. The present study reports on the metabolite profiles of a Lion's Mane mushroom (Hericium erinaceus) strain and a strain of the rare species,Hericium flagellum(synonymH. alpestre). While we observed highly similar metabolite profiles between the two strains that were examined, we isolated two previously undescribed metabolites, given the trivial names erinacines Z1 and Z2. Their chemical structures were elucidated by means of nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry. Along with six further, previously identified cyathane diterpenes, the novel erinacines were tested for neurotrophin inducing effects. We found that erinacines act onBDNF, which is a neurotrophic factor that has been reported recently by us to be induced by the corallocins, but as well onNGFexpression, which is consistent with the literature.
    • Two New Triterpenes from Basidiomata of the Medicinal and Edible Mushroom laetiporus sulphureus .

      Hassan, Khadija; Matio Kemkuignou, Blondelle; Stadler, Marc; HZI, Helmholtz Zentrum für Infektionsforschung, GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (MDPI, 2021-11-24)
      In the search for novel anti-infectives from natural sources, fungi, in particular basidiomycetes, have proven to still harbor so much potential in terms of secondary metabolites diversity. There have been numerous reports on isolating numerous secondary metabolites from genus Laetiporus. This study reports on two new triterpenoids, laetiporins C and D, and four known triterpenes from the fruiting body of L. sulphureus. The structures of the isolated compounds were elucidated based on their 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data in combination with high-resolution electrospray mass spectrometric (HR-ESIMS) data. Laetiporin C exhibited weak antifungal activity against Mucor hiemalis. Furthermore, the compounds showed weak antiproliferative activity against the mouse fibroblast L929 and human cancer cell lines, including KB-3-1, A431, MCF-7, PC-3 and A549.
    • Two novel species of (Parabambusicolaceae, Pleosporales) with their phoma-like asexual morphs.

      Phukhamsakda, Chayanard; Bhat, Darbhe J; Hongsanan, Sinang; Xu, Jian-Chu; Stadler, Marc; Hyde, Kevin D; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-01-01)
      The monotypic genus
    • Two xanthones and two rotameric (3⟶8) biflavonoids from the Cameroonian medicinal plant Allanblackia floribunda Oliv. (Guttiferae)

      Mountessou, Bel Youssouf G.; Tchamgoue, Joseph; Paul Dzoyem, Jean; Tchuenguem, Roland T.; Surup, Frank; Choudhary, Muhammad I.; Green, Ivan R.; Kouam, Simeon F.; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Elsevier BV, 2018-12)
      Two xanthones, 2-(3-hydroxy-3,3-dimethyldihydroallyl)-dihydro-6-deoxyisojacareubin (1) and dihydro-6-deoxyjacareubin (2), and two 3 ⟶ 8 rotameric biflavonoids, (2R,3S)-volkensiflavone-7-O-β-acetylglucopyranoside (3) and (2S,3S)-morelloflavone-7-O-β-acetylglucopyranoside (4), together with fifteen known compounds, were isolated from a dichloromethane/methanol (1:1, v/v) extract of the bark of the plant Allanblackia floribunda. The structures of the new compounds were elucidated by NMR spectroscopy and mass spectroscopic techniques and those of the known ones were deduced by comparison with data reported in the literature. The isolated biflavonoids were obtained as mixtures of conformers exhibiting duplicate NMR signals in solution at 25 °C and their respective absolute configurations were assigned using circular dichroism spectroscopy. Selected isolated compounds were assessed for their antibacterial and antioxidant properties
    • Unambiguous identification of fungi: where do we stand and how accurate and precise is fungal DNA barcoding?

      Lücking, Robert; Aime, M Catherine; Robbertse, Barbara; Miller, Andrew N; Ariyawansa, Hiran A; Aoki, Takayuki; Cardinali, Gianluigi; Crous, Pedro W; Druzhinina, Irina S; Geiser, David M; et al. (BMC, 2020-07-10)
      True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.
    • An unprecedented spiro [furan-2,1’-indene]-3-one derivative and other nematicidal and antimicrobial metabolites from Sanghuangporus sp. (Hymenochaetaceae, Basidiomycota) collected in Kenya

      Chepkirui, Clara; Cheng, Tian; Matasyoh, Josphat; Decock, Cony; Stadler, Marc; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany.
      Bioassay guided fractionation of extracts derived from submerged cultures of a Sanghuangporus sp. (i.e., the genus that was until recently referred to as the “Inonotus linteus complex” of medicinal mushrooms) originating from Kenya led to the isolation of a new spiro [furan-2,1’-indine]-3-one derivative, for which we propose the trivial name phelligridin L (1) together with the known compounds 3,14′-bihispidinyl (2), hispidin (3), ionylideneacetic acid (4), 1S-(2E)-5-[(1R)-2,2-dimethyl-6-methylidenecyclohexyl]-3-methylpent-2-enoic acid (5), phellidine E (6) and phellidine D (7). Compounds 1–3, showed moderate nematicidal activity against Caenorhabditis elegans with LD50 of 12.5 μg/m. The nematicidal activity of 3, 14′-bihispidinyl and hispidin (1, 2) has not been reported before. Furthermore, compounds 1–5 demonstrated moderate antimicrobial activity against various test organisms.
    • Unsaturated Fatty Acids Control Biofilm Formation of and Other Gram-Positive Bacteria.

      Yuyama, Kamila Tomoko; Rohde, Manfred; Molinari, Gabriella; Stadler, Marc; Abraham, Wolf-Rainer; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2020-11-08)
      Infections involving biofilms are difficult to treat due to increased resistances against antibiotics and the immune system. Hence, there is an urgent demand for novel drugs against biofilm infections. During our search for novel biofilm inhibitors from fungi, we isolated linoleic acid from the ascomycete Hypoxylon fragiforme which showed biofilm inhibition of several bacteria at sub-MIC concentrations. Many fatty acids possess antimicrobial activities, but their minimum inhibitory concentrations (MIC) are high and reports on biofilm interferences are scarce. We demonstrated that not only linoleic acid but several unsaturated long-chain fatty acids inhibited biofilms at sub-MIC concentrations. The antibiofilm activity exerted by long-chain fatty acids was mainly against Gram-positive bacteria, especially against Staphylococcus aureus. Micrographs of treated S. aureus biofilms revealed a reduction in the extracellular polymeric substances, pointing to a possible mode of action of fatty acids on S. aureus biofilms. The fatty acids had a strong species specificity. Poly-unsaturated fatty acids had higher activities than saturated ones, but no obvious rule could be found for the optimal length and desaturation for maximal activity. As free fatty acids are non-toxic and ubiquitous in food, they may offer a novel tool, especially in combination with antibiotics, for the control of biofilm infections.
    • Viridistratins A-C, Antimicrobial and Cytotoxic Benzo[]fluoranthenes from Stromata of (Hypoxylaceae, Ascomycota).

      Becker, Kevin; Wessel, Anna-Charleen; Luangsa-Ard, J Jennifer; Stadler, Marc; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2020-05-23)
      During the course of our search for novel biologically active metabolites from tropical fungi, we are using chemotaxonomic and taxonomic methodology for the preselection of interesting materials. Recently, three previously undescribed benzo[j]fluoranthenes (1-3) together with the known derivatives truncatones A and C (4, 5) were isolated from the stromata of the recently described species Annulohypoxylon viridistratum collected in Thailand. Their chemical structures were elucidated by means of spectral methods, including nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). The new compounds, for which we propose the trivial names viridistratins A-C, exhibited weak-to-moderate antimicrobial and cytotoxic activities in cell-based assays.
    • Viriditins from Byssochlamys spectabilis, their stereochemistry and biosynthesis

      López-Fernández, Sebastián; Campisano, Andrea; Schulz, Barbara J.; Steinert, Michael; Stadler, Marc; Surup, Frank; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Elsevier, 2020-01-30)