Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• overviews exist on mycotoxins in general [1][2][3], on selected Alternaria toxins [4][5][6][7][8][9][10][11][12], and on dibenzo-α-pyrones [13][14][15][16][17][18][19]. The current review will comprehensively deal with all naturally occurring polyketides derived from β-resorcylic acid (2,4-dihydroxybenzoic

• describing the occurrence of these mycotoxins in feedstuffs are scarce and are not sufficient to assess the risk regarding Alternaria toxins for animal health,” [9] and encouraged further investigations on Alternaria toxins in many areas. Review Alternariol-derived resorcylic lactones Alternariol and its

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• by acting as pathogens. It is firmly established that the ability to produce mycotoxins contributes to the virulence potential of these fungi, but as they all thrive in environmental reservoirs they must also provide an ecological advantage to their producer [18]. Indeed, many of these pathogenic

• fungi also produce compounds with antibacterial, antifungal and insecticidal properties to ward of both competitors and predators. The mycotoxins aflatoxin B1 (1) from Aspergillus flavus and patulin (2), produced by Aspergillus and Penicillium species, exhibit insecticidal activity against Drosophila

• melanogaster and might thus prevent feeding competition [19][20][21] (Figure 2). But not only mycotoxins protect from predation: A. flavus sclerotia are protected from sap beetles by asparasone and Neurospora crassa’s neurosporin A prevents springtail grazing [22][23]. Grazing by Folsomia candida springtails

Total synthesis of decarboxyaltenusin

• Lucas Warmuth,
• Aaron Weiß,
• Marco Reinhardt,
• Anna Meschkov,
• Ute Schepers and
• Joachim Podlech

Beilstein J. Org. Chem. 2021, 17, 224–228, doi:10.3762/bjoc.17.22

• -3,5-dimethoxybenzene, where the longest linear sequence consists of five steps. The key reaction was a palladium-catalyzed Suzuki coupling of an aromatic boronate with a brominated resorcin derivative. Keywords: biaryls; boronates; mycotoxins; polyketides; Suzuki coupling; Introduction 5’-Methoxy-6

• compound due to the reduced accessibility of the precursors and since no experimental details have been published for the transformation. To continue our efforts in the total synthesis of mycotoxins [8][9][10][11][12][13][14][15][16][17][18] and to provide larger amounts of the polyketide 1 sufficient for

• . Biphenyl-derived mycotoxins. Synthesis of arylboronates 6. Conditions: a) TBSCl, DMAP, imidazole, DMF, 50 °C, 4 h (96%); b) NBS, MeCN, rt, 71 h (quant.); c) NBS, MeCN, rt, 72 h (R = TBS, 96%); d) BnBr, KI, K2CO3, DMF/acetone, 70 °C, 29 h, (R = Bn, 86%); e) R = TBS: BuLi, 2-isopropoxy-4,4,5,5-tetramethyl

Absolute configurations of talaromycones A and B, α-diversonolic ester, and aspergillusone B from endophytic Talaromyces sp. ECN211

• Ken-ichi Nakashima,
• Junko Tomida,
• Takao Hirai,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 290–296, doi:10.3762/bjoc.16.28

• : secalonic acids, ergoflavins, and ergochrysins), which are well-known mycotoxins that exhibit toxic, antibacterial, and mutagenic properties [1]. On the other hand, a limited number of monomeric tetrahydroxanthones has been reported as fungal metabolites to date, including the blennolides [2], diversonolic

Isolation of fungi using the diffusion chamber device FIND technology

• Benjamin Libor,
• Henrik Harms,
• Stefan Kehraus,
• Ekaterina Egereva,
• Max Crüsemann and
• Gabriele M. König

Beilstein J. Org. Chem. 2019, 15, 2191–2203, doi:10.3762/bjoc.15.216

• were limited to mycotoxins [34] where in the other cases the isolated structures showed remarkable activities in the field of anticancer and antimicrobial agents [35][36][37][38][39][40]. H. alpina is one of only six species known from the less examined genus Heydenia, and was mistaken for a member of

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• mycotoxins [2], a class of highly bioactive secondary metabolites that belong to the strongest known inhibitors of protein biosynthesis in eukaryotes [3]. Similarly, the sesquiterpene aristolochene (2) is the parent hydrocarbon of PR toxin [4][5] and has been used as a marker to differentiate between toxin

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• spore distribution [11]. Furthermore, volatiles can be used as taxonomic markers [12] and can serve as indicators for fungal toxin production, e.g., the fungal emission of the sesquiterpene hydrocarbon trichodiene points to the production of trichothecene mycotoxins [13]. Aspergillus is a well-described

Volatiles from the tropical ascomycete Daldinia clavata (Hypoxylaceae, Xylariales)

• Tao Wang,
• Kathrin I. Mohr,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 135–147, doi:10.3762/bjoc.14.9

• biocontrol agents [6]. On the contrary, fungi can also produce mycotoxins, which must be excluded for their safe usage in agricultural biocontrol. Some volatiles, especially terpenes, point to the production of certain toxins in fungi, e.g., aristolochene (3) is the precursor of PR toxin in Penicillium

• roqueforti [7][8][9], trichodiene (4) is the parent hydrocarbon of the trichothecene family of mycotoxins in various Trichothecium and Fusarium strains [10], and the diterpene ent-kaurene (5) is the precursor of gibberellins, a class of plant hormones that are produced in large amounts by the rice pathogen

• hazardous mycotoxins. Similar studies on other fungal cultures with proven initial antagonistic activities that can be related to VOCs will probably be rewarding. Total ion chromatogram of a representative headspace extract from Daldinia clavata MUCL 47436. Peak numbers refer to compound numbers in Scheme 2

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• of fumonisin mycotoxins produced by fungi of the genus Fusarium, a common grain mold. It is a close structural analogue of fumonisin B1, the most prevalent member of the family of fumonisins [79][80]. Fumonisin B1, B2 and other fumonisins frequently contaminate maize and other crops [81][82][83

Synthesis of zearalenone-16-β,D-glucoside and zearalenone-16-sulfate: A tale of protecting resorcylic acid lactones for regiocontrolled conjugation

• Hannes Mikula,
• Julia Weber,
• Dennis Svatunek,
• Philipp Skrinjar,
• Gerhard Adam,
• Rudolf Krska,
• Christian Hametner and
• Johannes Fröhlich

Beilstein J. Org. Chem. 2014, 10, 1129–1134, doi:10.3762/bjoc.10.112

• sulfate that are highly valuable as reference materials for further studies in the emerging field of masked mycotoxins. Furthermore, high stability was observed for aryl sulfates prepared as tetrabutylammonium salts. Overall, these findings should be applicable for the synthesis of similar RAL type and

• natural product conjugates. Keywords: glycosylation; masked mycotoxins; resorcylic acid esters; sulfation; zearalenone; Introduction Resorcylic acid lactones (RALs, Figure 1), a compound class of benzannulated macrolides, are pharmacologically active secondary metabolites produced by a variety of

• mycotoxins, especially altered derivatives formed through conjugation to sugar moieties or sulfate, emerge after metabolization by living plants. Due to changed chemical structures and properties compared to the parent mycotoxins, these conjugates can usually not be detected applying standard analytical