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Search for "toxin" in Full Text gives 52 result(s) in Beilstein Journal of Organic Chemistry.
Natural resorcylic lactones derived from alternariol
Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187
- ][57]. Its biosynthetic origin from acetate units by feeding 1-14C-labeled acetate precursors was recognized soon after [58][59], where more details on its biosynthesis are given in the respective chapter (vide infra). Alternariol is the main toxin produced by A. alternata and was isolated from further
- ][68] and syntheses of labeled alternariol [69][70]. Selected syntheses will be given in the chapter on total syntheses (vide infra). The ubiquity and easy availability of this toxin by microbiological and synthetic methods (5 g of the compound were once synthesized in the group of the author) allowed
- -methylalternariol (2), mostly referred to as alternariol 9-methyl ether, usually abbreviated with AME, and occasionally named djalonensone. It is almost as abundant as alternariol itself and it is hardly possible to catch up with the number of publications on this toxin; the SciFinder database gives at now more
Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria
Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75
- enzyme of the Krebs cycle [25]. Therefore, NNG may be a toxin released to kill or outcompete nearby bacteria or other organisms for limited resources. In such a context, the physiological function of NnlA could be to protect bacteria from toxic NNG exposure. Alternatively, NnlA could be a promiscuous
Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium
Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57
- produced by the marine Okeania sp. cyanobacterium. In the field, this type of cyanobacterium that produces the analog of human lethal toxin is often observed with macroalgae and shells, and, therefore, it can be a potential risk for food poisoning of fishery resources. Experimental General experimental
Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus
Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124
- chemical defence, e.g., by toxin production [6]. With penicillin as the prime example fungal secondary metabolites have raised scientific and pharmaceutical interests for nearly one century. Today’s sequencing and bioinformatic analyses of fungal genomes revealed that the genetic potential far exceeds the
- epipolythiodioxopiperazine (ETP’s) class toxin of several fungal genera including Aspergillus, Penicillium, Trichoderma, and Leptosphaera (Figure 3) [112]. Among the ascomycetes, A. fumigatus may well be the major GT producer and the identification of its heterocyclic structure by Bell and colleagues in 1958 builds the
- , comparable to how Trichoderma virens protects cotton seedlings from its pathogen Pythium ultimum [122]. Trypacidin The spore-born toxin trypacidin (8) is a polyketide that belongs to an anthraquinone-derived class of secondary metabolites (Figure 4) [107]. In A. fumigatus, the trypacidin biosynthetic cluster
Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications
Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116
Total synthesis of ent-pavettamine
Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99
- Memory Zimuwandeyi Manuel A. Fernandes Amanda L. Rousseau Moira L. Bode Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO WITS, 2050, South Africa 10.3762/bjoc.17.99 Abstract Pavettamine, a plant toxin first isolated from Pavetta harborii in
- substituted methylene linkage. Biological studies have shown that this toxin is responsible for “quick disease” (gousiekte) in ruminant animals, which causes inhibition of protein synthesis in the cardiovascular organs [13]. The unique structure coupled with the biological effects of this polyamine prompted
Synthetic accesses to biguanide compounds
Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82
Total synthesis of decarboxyaltenusin
Beilstein J. Org. Chem. 2021, 17, 224–228, doi:10.3762/bjoc.17.22
- -Leopoldshafen, Hermann-von-Helmholtz-Platz 1, Germany 10.3762/bjoc.17.22 Abstract The total synthesis of decarboxyaltenusin (5’-methoxy-6-methyl-[1,1’-biphenyl]-3,3’,4-triol), a toxin produced by various mold fungi, has been achieved in seven steps in a yield of 31% starting from 4-methylcatechol and 1-bromo
Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine
Beilstein J. Org. Chem. 2021, 17, 28–41, doi:10.3762/bjoc.17.4
- and toxin [(−)-adaline] content of A. bipunctata eggs, once the maternal and paternal aposematic phenotype had the most significant effect on egg traits if compared to the maternal responses to offspring predators. Thus, the phenotype can also contribute to the aposematic signal variation in a
Fabclavine diversity in Xenorhabdus bacteria
Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84
- , Supporting Information File 1). Nevertheless, X. innexi contains a tonB-homologue instead of the NUDIX-hydrolase fclA and an acyl-CoA-thioesterase instead of fclM and fclN, leading to the postulated compound Xenorhabdus lipoprotein toxin (Xlt, Figure S1, Supporting Information File 1) [27]. Furthermore
Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin
Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46
- for ricin toxin A (RTA) inhibitors [14]. By deprotonation of the lactam NH, and conversion to the DBU salt, the pterin easily dissolves in methanol at high concentrations, unprecedented for unfunctionalized pterins. This greatly accelerated the development of a library of bioactive pterins, as it
Bipolenins K–N: New sesquiterpenoids from the fungal plant pathogen Bipolaris sorokiniana
Beilstein J. Org. Chem. 2019, 15, 2020–2028, doi:10.3762/bjoc.15.198
- fungi against plant hosts [12]. Well-known examples include the host-specific toxins victorin and T-toxin and other non-host-specific toxins such as the ophiobolins [11]. Bipolaris sorokiniana (syn. Cochliobolus sativus) has been identified as the causative agent of multiple diseases on wheat and barley
Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce
Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27
- summer season in the highland areas of Japan (e.g., Nagano and Iwate prefectures) was isolated. The structure of a toxin produced by this organism was analyzed based on the detailed evaluation of its 2D NMR and FABMS spectra, and this compound has not been reported previously. We propose the name
- cichorinotoxin for this toxin. In conjunction with the D or L configurations of each amino acid, which were determined by Marfey’s method, we propose the structure of cichorinotoxin to be as follows: 3-hydroxydecanoyl-(Z)-dhThr1-D-Pro2-D-Ala3-D-Ala4-D-Ala5-D-Val6-D-Ala7-(Z)-dhThr8-Ala9-Val10-D-Ile11-Ser12-Ala13
- -Val14-Ala15-Val16-(Z)-dhThr17-D-alloThr18-Ala19-L-Dab20-Ser21-Val22, and an ester linkage is present between D-alloThr18 and Val22 (dhThr: 2-aminobut-2-enoic acid; Dab: 2,4-diaminobutanoic acid). Thus, the toxin is a lipodepsipeptide with 22 amino acids. The mono- and tetraacetate derivatives and two
Synthesis of a tubugi-1-toxin conjugate by a modulizable disulfide linker system with a neuropeptide Y analogue showing selectivity for hY1R-overexpressing tumor cells
Beilstein J. Org. Chem. 2019, 15, 96–105, doi:10.3762/bjoc.15.11
- )-inspired peptide [K4(C-βA-),F7,L17,P34]-hNPY, acting as NPY Y1 receptor (hY1R)-targeting peptide, to form a tubugi-1–SS–NPY disulfide-linked conjugate. The cytotoxic impacts of the novel tubugi-1–NPY peptide–toxin conjugate, as well as of free tubugi-1, and tubugi-1 bearing the thiol spacer (liberated from
- (Ewing`s sarcoma), MDA-MB-468, MDA-MB-231 (both breast cancer) and 184B5 (normal breast; chemically transformed) were investigated. As hoped, the toxicity of tubugi-1 was masked, with IC50 values decreased by ca. 1,000-fold compared to the free toxin. Due to intracellular linker cleavage, the cytotoxic
- potency of the liberated tubugi-1 that, however, still bears the thiol spacer (tubugi-1-SH) was restored and up to 10-fold higher compared to the entire peptide–toxin conjugate. The conjugate shows toxic selectivity to tumor cell lines overexpressing the hY1R receptor subtype like, e.g., the hard to treat
Lectins of Mycobacterium tuberculosis – rarely studied proteins
Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1
- associated with intercellular binding, cell–cell recognition, intracellular protein trafficking, and toxin activity [26]. Lectins typically possess high carbohydrate ligand specificity, enabling precise control over protein–target contacts and associated downstream processes. Lectins are often easily
- infections in humans, presumably through interference with lectin-associated pathogen–host adhesion [67][68]. Besides facilitation of adhesion, some bacterial lectins are also known to act as toxins. The secreted pertussis toxin, for example, is a lectin and an important virulence factor of Bordetella
- pertussis [69][70][71], the bacterial pathogen responsible for the respiratory disease pertussis, or whooping cough. While no reports exist to date, inhibiting the adhesion of the pertussis toxin to host–cell surface carbohydrates using carbohydrate ligand mimics might permit reduction of the pathogenicity
Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum
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
Synthesis of pyrrolidine-based hamamelitannin analogues as quorum sensing inhibitors in Staphylococcus aureus
Beilstein J. Org. Chem. 2018, 14, 2822–2828, doi:10.3762/bjoc.14.260
- , Foodborne Toxin Detection & Prevention Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA 10.3762/bjoc.14.260 Abstract Interfering with bacterial cell-to-cell communication is a promising strategy to combat antimicrobial resistance. The natural
Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products
Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245
- . Bacterial cultures were grown for eight hours in the presence of each compound, followed by extraction of the pyocyanin under acidic conditions [22]. This was then quantified by measurement of the OD520, which corresponds to absorption by the toxin. The results are shown in Figure 4, normalised by the
Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers
Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241
- unconventional strategy has been provided recently by the approval of the toxin-neutralizing therapeutic antibody bezlotoxumab, which is henceforth in clinical use for pre-emptive treatment of recurring clostridial infections [10]. So, the potential of active principles, which do not kill the bacteria through
Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections
Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239
- plasma and liver microsomes, absence of cytotoxicity, and excellent oral bioavailability in mice. 4. Direct toxin inhibition Numerous bacteria secrete toxins that are responsible for acute virulence. Various small molecule and antibody approaches target the inhibition of bacterial toxins in order to
- antagonize bacterial virulence [51]. AB toxins are widespread among species and consist of a catalytically active A-domain and one or more units of a receptor-binding domain B. The B domain is responsible for binding to a cell-surface receptor, which engages in receptor-mediated cellular uptake. The AB toxin
- . Numerous inhibitors have been developed against AB toxins, targeting toxin transcription, assembly, receptor binding and enzyme function [51]. A set of antibodies against diverse toxins has recently been approved for therapeutic use, which demonstrates the scientific and medical feasibility of entering the
Natural and redesigned wasp venom peptides with selective antitumoral activity
Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144
- (ATCC) were maintained in a mixture of Dulbecco’s Modified Eagle’s Medium and Ham’s F12 nutrient mixture supplemented with 5% inactivated horse serum, 10 μg mL−1 insulin, 0.02 μg mL−1 human epidermal growth factor, 0.5 μg mL−1 hydrocortisone, 0.10 μg mL−1 choleric toxin, 100 U mL−1 penicillin, and 100
Design and biological characterization of novel cell-penetrating peptides preferentially targeting cell nuclei and subnuclear regions
Beilstein J. Org. Chem. 2018, 14, 1378–1388, doi:10.3762/bjoc.14.116
- protein importin-α at the nuclear envelope and triggers the uptake of the transcription factor NF-κB [22][23]. As second sequence we chose the NrTP sequence, which is a designed peptide coming from the rattlesnake toxin, called crotamine [3]. For both peptides, preferential accumulation within the nuclei
Novel unit B cryptophycin analogues as payloads for targeted therapy
Beilstein J. Org. Chem. 2018, 14, 1281–1286, doi:10.3762/bjoc.14.109
- not better than its parent. In recent years the targeted delivery of cytotoxic agents has emerged as a highly promising method to tackle selectivity issues [36][37][38][39][40]. Cryptophycin-52 and many analogues lack an addressable group to conjugate the toxin to a homing device. For this reason, new
Volatiles from three genome sequenced fungi from the genus Aspergillus
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
Carbohydrate inhibitors of cholera toxin
Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34
- Vajinder Kumar W. Bruce Turnbull Department of Chemistry, Akal University, Talwandi Sabo, Punjab, India School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, UK 10.3762/bjoc.14.34 Abstract Cholera is a diarrheal disease caused by a protein toxin
- released by Vibrio cholera in the host’s intestine. The toxin enters intestinal epithelial cells after binding to specific carbohydrates on the cell surface. Over recent years, considerable effort has been invested in developing inhibitors of toxin adhesion that mimic the carbohydrate ligand, with
- particular emphasis on exploiting the multivalency of the toxin to enhance activity. In this review we introduce the structural features of the toxin that have guided the design of diverse inhibitors and summarise recent developments in the field. Keywords: carbohydrate; cholera; multivalency; toxin
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