Isolation, structure elucidation, and biological evaluation of the unusual heterodimer chrysoxanthone from the ascomycete IBWF11-95A

Chrysoxanthone, an unusual heterodimer of blennolide A and 2-hydroxychrysophanol linked through a diaryl ether bridge, was isolated from mycelia of the ascomycete IBWF11-95A grown in submerged culture. Its structure was elucidated by two-dimensional NMR spectroscopy. The metabolite shows antibacterial activity against different species with MIC values between 2.5 and 20 μg/mL while also inhibiting the growth of several fungi.

Omphalotins E-I, Five Oxidatively Modified Nematicidal Cyclopeptides fromOmphalotus olearius

Omphalotins E–I, oxidatively modified cyclic dodecapeptides, were isolated from mycelial extracts of the basidiomycete Omphalotus olearius, and their structures were determined by NMR spectroscopic and MS methods. Four of the five omphalotins contained an unprecedented N-hydroxylated tricyclic tryptophan derivative. All compounds exhibited strong and selective nematicidal activity against the plant pathogen Meloidogyne incognita with LD90 values between 2 and 5 μg mL–1. Cytotoxic activities were not detected up to 50 μg mL–1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

4-Dechloro-14-deoxy-oxacyclododecindione and 14-deoxy-oxacylododecindione, two inhibitors of inducible connective tissue growth factor expression from the imperfect fungus Exserohilum rostratum

Connective tissue growth factor (CTGF/CCN2), a member of the CCN superfamily of secreted cysteine-rich glycoproteins, is a central mediator of tissue remodeling and fibrosis. CTGF is suggested to be an important down-stream effector of transforming growth factor-beta (TGF-β) signaling and has therefore reached considerable pathophysiological relevance because of its involvement in the pathogenesis of fibrotic diseases, atherosclerosis, skin scarring, and other conditions with excess production of connective tissue. In a search for inhibitors of inducible CTGF expression from fungi, two new macrocyclic lactones, namely 4-dechloro-14-deoxy-oxacyclododecindione (1) and 14-deoxy-oxacylododecind…

Data handling in NMR facilities and assignment of NMR spectra in synthetic chemistry labs: Why electronic structure validation should become part of the routine.

GKK1032A2, a secondary metabolite from Penicillium sp. IBWF-029-96, inhibits conidial germination in the rice blast fungus Magnaporthe oryzae

GKK1032A 2 , a secondary metabolite from Penicillium sp. IBWF-029-96, inhibits conidial germination in the rice blast fungus Magnaporthe oryzae

Drimane Sesquiterpenoids from Marasmius sp. Inhibiting the Conidial Germination of Plant-Pathogenic Fungi

From the basidiomycete Marasmius sp., strain IBWF 96046, three new sesquiterpenoids based on the drimane skeleton were isolated and named marasmene B and marasmals B and C. In this study, their isolation, structure elucidation, and biological evaluation are described. The compounds have a pronounced inhibitory effect on the conidial germination of several plant-pathogenic fungi.

Unexpected Behavior of Enaminones: Interesting New Routes to 1,6-Naphthyridines, 2-Oxopyrrolidines and Pyrano[4,3,2-de][1,6]naphthyridines

Reaction of enaminones 1a–d with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9a–d. On the other hand, 2-aminopyrano[4,3,2-de] [1,6]naphthyridine-3-carbonitriles 20a–c,e were the only obtained products from the reactions of 1a–d with 2 in the presence of AcOH/NaOAc, while 1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone 21 under the same condition. The reaction of 2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid eth…

Isolactarane and Sterpurane Sesquiterpenoids from the Basidiomycete Phlebia uda

Three new sesquiterpenoids, named udasterpurenol A, udalactarane A, and udalactarane B, as well as the known compounds hyphodontal and sterpuric acid have been isolated from the basidiomycete Phlebia uda. These compounds represent the first natural products described from this species. The structures were elucidated by NMR spectroscopy and mass spectrometry. Udalactaranes A and B were isolated as mixtures with their respective epimeric acetals. These mixtures inhibited the spore germination of the plant pathogenic fungus Fusarium graminearum at 10 and 5 μg/mL, respectively, and were active against Jurkat cells with IC(50) values of 101 and 42 μM, respectively.

Cover Feature: Research Data in Chemistry – Results of the first NFDI4Chem Community Survey (Z. Anorg. Allg. Chem. 23‐24/2020)

Elucidation of the biosynthesis and degradation of allantofuranone by isotopic labelling and fermentation of modified precursors.

Feeding experiments with the ascomycete Allantophomopsis lycopodina indicated that the potent fungistatic allantofuranone is biosynthesized from phenylalanine. Further experiments with synthetic precursors gave evidence that the naturally occurring polyporic acid serves as a key intermediate in the biosynthesis. In addition to the formation of allantofuranone, its abiotic and metabolic degradation were investigated.

Donellanic acids A–C: new cyclopropanic oleanane derivatives from Donella ubanguiensis (Sapotaceae)

Abstract Three new cyclopropanic oleanane triterpenoids and ten known compounds were obtained from Donella ubanguiensis using chromatographic methods. The structures were established on the basis of mass spectrometric and NMR data and by comparison with values reported in the literature. The structures of the new compounds were confirmed by X-ray crystallography. A part of the isolated compounds was evaluated for cytotoxic and antimicrobial activities.

Omphalocarpoidone, a new lanostane-type furano-spiro-γ-lactone from the wood of Tridesmostemon omphalocarpoides Engl. (Sapotaceae)

Abstract Phytochemical studies of the wood and the stem bark of Tridesmostemon omphalocarpoides Engl. (Sapotaceae) led to the isolation of omphalocarpoidone (1), a new lanostane-type furano-spiro-γ-lactone together with β-amyrin acetate (2), taraxerol (3), spinasterol (4), lichexanthone (5), epi-catechin (6), spinasterol 3-O-β- d -glucopyranoside (7), tormentic acid (8), and 1,2,3,4-tetrahydronorharman-1-one (9). Their structures were established on the basis of extensive NMR studies, mass spectrometry, and by comparison of the data with those previously reported in the literature. The structure of the new secondary metabolite was later confirmed by X-ray crystallography. Except for spinast…

Hirsutane-Type Sesquiterpenes with Uncommon Modifications from Three Basidiomycetes

From three basidiomycetes, Xeromphalina sp., Stereum sp., and Pleurocybella porrigens, six triquinane sesquiterpenes with unprecendented modifications and a rearranged sesquiterpene related to coriolin C have been isolated. Their isolation, structure elucidation, and biological evaluation are described.

Assignment of Configuration in a Series of Dioxolanone-Type Secondary Metabolites fromGuignardia bidwellii- A Comparison of VCD and ECD Spectroscopy

The absolute configurations of a series of phytotoxic dioxolanone-type secondary metabolites isolated from culture filtrates of the grape black rot fungus Guignardia bidwellii were determined by vibrational circular dichroism (VCD) spectroscopy in the mid-IR frequency range. Comparison of the recorded data with DFT calculations showed good agreement between experiment and theory for VCD, whereas electronic circular dichroism (ECD) data for the compounds matched poorly with the predicted spectra obtained by time-dependent DFT (TDDFT) calculations at the same level of theory.

Unravelling the biosynthesis of pyriculol in the rice blast fungus Magnaporthe oryzae

Pyriculol was isolated from the rice blast fungus Magnaporthe oryzae and found to induce lesion formation on rice leaves. These findings suggest that it could be involved in virulence. The gene MoPKS19 was identified to encode a polyketide synthase essential for the production of the polyketide pyriculol in the rice blast fungus M. oryzae. The transcript abundance of MoPKS19 correlates with the biosynthesis rate of pyriculol in a time-dependent manner. Furthermore, gene inactivation of MoPKS19 resulted in a mutant unable to produce pyriculol, pyriculariol and their dihydro derivatives. Inactivation of a putative oxidase-encoding gene MoC19OXR1, which was found to be located in the genome cl…

Ganodermycin, a novel inhibitor of CXCL10 expression from Ganoderma applanatum

CXCL10 (inducible protein-10) is a highly inducible chemoattractant, which contributes to the recruitment of inflammatory cells, such as macrophages and T-lymphocytes, and thereby has important roles in chronic inflammatory conditions. In a search for new inhibitors of CXCL10 expression in MonoMac6 cells, a novel compound, designated as Ganodermycin, was isolated from fermentations of the basidiomycete Ganoderma applanatum. The structure was determined by a combination of spectroscopic techniques. Ganodermycin inhibited the lipopolysaccharide (LPS)/interferon (IFN)-γ-induced CXCL10 promoter activity in transiently transfected MonoMac6 cells in a dose-dependent manner with IC(50) values of 1…

Synthesis of Lamellarin U and Lamellarin G Trimethyl Ether by Alkylation of a Deprotonated α-Aminonitrile

1,2,3,4-Tetrahydroisoquinoline-1-carbonitriles can serve as starting materials for the one-pot synthesis of 5,6-dihydropyrrolo[2,1 a]isoquinolines and 1-benzyl-3,4-dihydroisoquinolines. The latter compounds were transformed to lamellarin G trimethyl ether and lamellarin U in short reaction sequences. This method allows the introduction of acid-sensitive protecting groups for the phenolic hydroxy functions which would be cleaved under the harsh conditions of the classical Bischler-Napieralski reaction.

ChemInform Abstract: Omphalotins E-I, Five Oxidatively Modified Nematicidal Cyclopeptides from Omphalotus olearius.

Omphalotins E–I, oxidatively modified cyclic dodecapeptides, were isolated from mycelial extracts of the basidiomycete Omphalotus olearius, and their structures were determined by NMR spectroscopic and MS methods. Four of the five omphalotins contained an unprecedented N-hydroxylated tricyclic tryptophan derivative. All compounds exhibited strong and selective nematicidal activity against the plant pathogen Meloidogyne incognita with LD90 values between 2 and 5 μg mL–1. Cytotoxic activities were not detected up to 50 μg mL–1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Electrochemical formation of N,N′-diarylhydrazines by dehydrogenative N–N homocoupling reaction

Hydrazines represent a class of compounds of high interest due to their applicability as versatile starting materials in many important transformations. Herein, we report a synthetic approach to hydrazine derivatives using commercially available anilines and an anodic dehydrogenative N-N coupling reaction as the key step.

3′-Demethyldihydromaldoxin and dihydromaldoxin, two anti-inflammtory diaryl ethers from a Steganospora species

CXCL10 (IP-10) is a highly inducible chemoattractant, which contributes to the recruitment of inflammatory cells such as macrophages and T-lymphocytes and thereby has important roles in chronic inflammatory conditions. In a search for new inhibitors of CXCL10 expression in MonoMac6 (MM6) cells, the new diaryl ether 3'-demethyldihydromaldoxin (1) along with the known compound dihydromaldoxin (2), were isolated from fermentations of a Steganospora species. The structures of the compounds were elucidated by a combination of one- and two-dimensional NMR spectroscopy and mass spectrometry. Compounds (1) and (2) inhibited lipopolysaccharide (LPS)/interferon-γ (IFN-γ)-induced CXCL10 promoter activ…

Phytotoxic dioxolanone-type secondary metabolites from Guignardia bidwellii.

Phenguignardic acid was recently described as a phytotoxic secondary metabolite from submerged cultures of the grape black rot fungus Guignardia bidwellii. Since the production rate of this natural product in submerged culture is very low, fermentation optimisation was carried out. The optimisation of cultivation conditions led to the identification of seven secondary metabolites, structurally related to guignardic acid, a known secondary metabolite from Guignardia species containing a dioxolanone moiety. All metabolites presented here have not been described to date and are presumably biosynthesised via deamination products of amino acids, such as phenylalanine, valine, tyrosine, and alani…

Terphenyl Derivatives from Allantophomopsis lycopodina.

Three secondary fungal metabolites 1–3 with a benzo[b]naphtho[2,1-d]furan skeleton were isolated from submerged cultures of the ascomycete Allantophomopsis lycopodina. The NMR-based structure elucidation was challenging due to a low H/C ratio of only 0.64 and 0.68, respectively. NMR measurements in two different solvents and the use of NMR experiments such as HSQC-TOCSY and LR-HSQMBC proved to be helpful in this respect. The proposed structures obtained from the comprehensive analysis of the NMR data were verified by comparison of recorded and computed NMR chemical shifts from quantum chemical calculations of several constitutional isomers and were further analyzed with the aid of the DP4 a…

Research Data in Chemistry : Results of the first NFDI4Chem Community Survey

Zeitschrift für anorganische und allgemeine Chemie : ZAAC 646(21), 1748-1757 (2020). doi:10.1002/zaac.202000339

ChemInform Abstract: Ganodermycin, a Novel Inhibitor of CXCL10 Expression from Ganoderma applanatum.

Ganodermycin (I), a novel inhibitor of CXCL10 expression, is isolated from Ganoderma applanatum.

Phenguignardic acid and guignardic acid, phytotoxic secondary metabolites from Guignardia bidwellii.

Bioactivity-guided isolation led to the identification of phenguignardic acid (2), a new phytotoxic secondary metabolite from submerged cultures of grape black rot fungus, Guignardia bidwellii. The compound is structurally related to guignardic acid (1), a dioxolanone moiety-containing metabolite isolated previously from Guignardia species. However, in contrast to guignardic acid, which is presumably synthesized from deamination products of valine and phenylalanine, the biochemical precursor for the biosynthesis of the new phytotoxin appears to be exclusively phenylalanine. Guignardic acid was also found in extracts of cultures from Guignardia bidwellii. The phytotoxic activities of both co…

Oxacyclododecindione, a Novel Inhibitor of IL-4 Signaling from Exserohilum rostratum

In a screening program for new metabolites from fungi inhibiting the IL-4 mediated signal transduction, a novel chlorinated macrocyclic lactone, designated as oxacyclododecindione, was isolated from fermentations of the imperfect fungus Exserohilum rostratum. The structure was determined by a combination of spectroscopic techniques. Oxacyclododecindione inhibits the IL-4 induced expression of the reporter gene secreted alkaline phosphatase (SEAP) in transiently transfected HepG2 cells with IC50 values of 20-25 ng/ml (54-67.5 nM). Studies on the mode of action of the compound revealed that the inhibition of the IL-4 dependent signaling pathway is caused by blocking the binding of the activat…

Conventional Oxyanionic versus Monomer-Activated Anionic Copolymerization of Ethylene Oxide with Glycidyl Ethers: Striking Differences in Reactivity Ratios.

Detailed understanding of the monomer distribution in copolymers is essential to tailor their properties. For the first time, we have been able to utilize in situ 1H NMR spectroscopy to monitor the monomer-activated anionic ring opening copolymerization (AROP) of ethylene oxide (EO) with a glycidyl ether comonomer, namely, ethoxy ethyl glycidyl ether (EEGE). We determine reactivity ratios and draw a direct comparison to conventional oxyanionic ROP. Surprisingly, the respective monomer reactivities differ strongly between the different types of AROP. Under conventional oxyanionic conditions similar monomer reactivities of EO and EEGE are observed, leading to random structures (rEO = 1.05 ± 0…

Unambiguous structure elucidation of heterocyclic products from condensation-cyclisation reactions of enaminones by 2D INADEQUATE and 15 N NMR

The reaction of enaminones with 3-amino-2-cyanopent-2-enedinitrile can lead to an array of 12 possible products, depending on the reaction pathway and tautomerization. The use of 2D INADEQUATE and 15N NMR for the unambiguous structure elucidation of the reaction products is discussed in this manuscript. Copyright © 2012 John Wiley & Sons, Ltd.

Copolymerization Kinetics of Glycidol and Ethylene Oxide, Propylene Oxide, and 1,2-Butylene Oxide: From Hyperbranched to Multiarm Star Topology

Copolymerization of established epoxide monomers with glycidol (G) is a key reaction to prepare branched or hyperbranched polyethers. The kinetics of the multibranching anionic ring-opening copolymerization of glycidol (a cyclic latent AB2 monomer) with ethylene oxide (EO), propylene oxide (PO), and 1,2-butylene oxide (BO; cyclic latent AB monomers), respectively, in dimethyl sulfoxide was studied. Online 1H NMR spectroscopy was employed for in situ monitoring of the individual monomer consumption during the entire course of the statistical copolymerization. Varying the counterion, both the cesium alkoxide and potassium alkoxide initiated copolymerization were studied and compared. From the…

CCDC 1979131: Experimental Crystal Structure Determination

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CCDC 861196: Experimental Crystal Structure Determination

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CCDC 942767: Experimental Crystal Structure Determination

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CCDC 838314: Experimental Crystal Structure Determination

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