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opencc-by-4.0Sep 2017View details →

Fig. 2 in Whole body solvent soak gives representative venom alkaloid profile from Solenopsis invicta (Hymenoptera: Formicidae) workers

Fig. 2. Gas chromatograms of hexane extracts obtained from Solenopsis invicta workers by different extraction methods. Capillary milking, gland dissection, and body without gland represent chromatograms from the sequential extraction of the same individual ants; whole body represents the chromatogram from whole body solvent-soaking extracts of 20 intact workers.

opencc-by-4.0Sep 2017View details →

Fig. 1 in Whole body solvent soak gives representative venom alkaloid profile from Solenopsis invicta (Hymenoptera: Formicidae) workers

Fig. 1. Total ion chromatogram of whole body solvent-soaking extract of 20 intact Solenopsis invicta workers in hexane.

opencc-by-4.0Oct 2019View details →

Quinolizidine alkaloids in food and feed - annexes on dietary surveys, occurrence data and dietary exposure assessment

Supplementary information to the Scientific opinion on the risks for animal and human health related to the presence of quinolizidine alkaloids in feed and food, in particular in lupins and lupin-derived products Annex A –     Dietary surveys and occurrence data in food submitted to EFSA Annex B –     Occurrence data in feed submitted to EFSA Annex C –     Results of acute dietary exposure assessment to quinolizidine alkaloids

opencc-by-4.0Nov 2022View details →

NMR data of alkaloids from Urceolina peruviana

This archive provides the description of the NMR data recorded for 13 alkaloids identified in an extract of the bulb of the South American plant Urceolina peruviana (C. Presl) J.F. Macbr (Amaryllidaceae): Tazettine 1 Albomaculine 2 Haemanthamine 3 Crinine 4 Trisphaeridine 5 3-Epimacronine 6 3-Methoxy-8,9-methylenedioxy-3,4-dihydrophenanthridine 7 Crinine acetate 8 6α-Hydroxybuphanisine 9 Nerinine 10 Pretazettine(6β-OH) 11A Pretazettine(6α-OH) 11B 6-Dehydroxy-6-acetamido-nerinine 12 See the README.txt file for more details.

opencc-zeroNov 2023View details →

Binding and sequestration of poison frog alkaloids by a plasma globulin

Alkaloids are important bioactive molecules throughout the natural world, and in many animals, they serve as a source of chemical defense against predation. Dendrobatid poison frogs bioaccumulate alkaloids from their diet to make themselves toxic or unpalatable to predators. Despite the proposed roles of plasma proteins as mediators of alkaloid trafficking and bioavailability, the responsible proteins have not been identified. We use chemical approaches to show that a ~50 kDa plasma protein is the principal alkaloid binding molecule in blood from poison frogs. Proteomic and biochemical studies establish this plasma protein to be liver-derived alkaloid-binding globulin (ABG) that is a member of the serine-protease inhibitor (serpin) family. In addition to alkaloid binding activity, ABG sequesters and regulates the bioavailability of "free" plasma alkaloids in vitro. Unexpectedly, ABG is not related to saxiphilin or albumin but instead exhibits sequence and structural homology to mammalian hormone carriers and amphibian biliverdin binding proteins. Alkaloid-binding globulin (ABG) represents a new small molecule binding functionality in serpin proteins, a novel mechanism of plasma alkaloid transport in poison frogs, and more broadly points towards serpins acting as tunable scaffolds for small molecule binding and transport across different organisms.

opencc-by-4.0Feb 2022View details →

Synthetic Studies towards Pyrido[1,2-a]azepine Stemona Alkaloids

The carbon skeleton of the Stemona alkaloids stemokerrin and cochinchistemonine was assembled from three building blocks (a piperidine, a furan, and a tetronate). Key steps linking the fragments included a Stille cross-coupling (piperidine/furan) and an aldol type addition of a tetronate. The furan served as a latent 1,4-difunctional compound which was converted to a gamma-hydroxylactone by a type II photooxygenation. Attempts to construct the C12-C13 double bond of stemokerrin by a late stage oxidation or by an elimination remained unsuccessful. The non-natural products dihydrostemokerrin and furostemokerrin were obtained instead.

opencc-by-4.0Feb 2022View details →

Synthetic Studies towards Pyrido[1,2-a]azepine Stemona Alkaloids

opencc-by-4.0May 2017View details →

Occurrence data on Pyrrolizidine Alkaloids (PAs) in food

The dataset contains data on the occurrence of Pyrrolizidine Alkaloids (PAs) in food products of plant origin, in particular herbal teas and food supplements from different geographic regions in Europe. A total of 359 samples were collected in years 2014 and 2015 and analysed for the presence of 28 PAs. Samples were collected in supermarkets, retail shops and for a small proportion via internet. The samples comprised 168 teas (including black, green, rooibos, chamomile, peppermint and mixed herbal tea) and 191 food supplements. The analytical method for determination of 1,2-unsaturated PAs is based on liquid chromatography combined with tandem mass spectrometry (LC-MS/MS), which complies with the requirements as described by the Commission regulation No. 401/2006. The updates in version 2 mainly refer to the analytical methods and the limits of quantification reported for the analysis of pyrrolizidine alkaloids in different food samples, and to some plant extracts for which wrong levels of pyrrolizidine alkaloids were reported by a data provider.

opencc-by-4.0Nov 2024View details →

Insights into Heterocycle Biosynthesis in the Cytotoxic Polyketide Alkaloid Janustatin A from a Plant-Associated Bacterium

Data underlying the manuscript 'Insights into Heterocycle Biosynthesis in the Cytotoxic Polyketide Alkaloid Janustatin A from a Plant-Associated Bacterium' by Leopold-Messer, Chawengrum and Piel. The repository contains: Sequencing data - Genbanks files of construct designs and ab1 files from Sanger sequencing. Contains both plasmids used to construct mutants, as well as sequencing data from final mutants. NMR data - MestReNova files of compounds 2-4. HPLC-MS data - Raw data collected on Thermo-Fisher instruments for the purified compounds (1-4) and the extract of all mutants.  EICs - extracted ion chromatograms used to analyse the metabolic differences between mutants. These data are based on the raw files. Bioactivity data - cytotoxicity data of compounds 1-4.

opencc-zeroNov 2022View details →

Poison frog dietary preference depends on prey type and alkaloid load

The ability to acquire chemical defenses through the diet has evolved across several major taxa. Chemically defended organisms may need to balance chemical defense acquisition and nutritional quality of prey items. However, these dietary preferences and potential trade-offs are rarely considered in the framework of diet-derived defenses. Poison frogs (Family Dendrobatidae) acquire defensive alkaloids from their arthropod diet of ants and mites, although their dietary preferences have never been investigated. We conducted prey preference assays with the Dyeing Poison frog (Dendrobates tinctorius) to test the hypothesis that alkaloid load and prey traits influence frog dietary preferences. We tested size preferences (big versus small) within each of four prey groups (ants, beetles, flies, and fly larvae) and found that frogs preferred interacting with smaller prey items of the fly and beetle groups. Frog taxonomic prey preferences were also tested as we experimentally increased their chemical defense load by feeding frogs decahydroquinoline, an alkaloid compound similar to those naturally found in their diet. Contrary to our expectations, overall preferences did not change during alkaloid consumption, as frogs across groups preferred fly larvae over other prey. Finally, we assessed the protein and lipid content of prey items and found that small ants have the highest lipid content while large fly larvae have the highest protein content. Our results suggest that consideration of toxicity and prey nutritional value are important factors in understanding the evolution of acquired chemical defenses and niche partitioning as a whole.

opencc-zeroMay 2023View details →

Virulence of three Aspergillus species to the model insect Galleria mellonella and the contribution of ergot alkaloids to the pathogenic potential of Aspergillus leporis

Opportunistically pathogenic fungi have varying potential to cause disease in animals. Factors contributing to their virulence include specialized metabolites, which is some cases evolved in contexts unrelated to pathogenesis. Specialized metabolites that increase fungal virulence in the model insect Galleria mellonella include the ergot alkaloids fumigaclavine C in Aspergillus fumigatus (syn. Neosartorya fumigata) and lysergic acid α-hydroxyethylamide (LAH) in the entomopathogen Metarhizium brunneum. Three species of Aspergillus recently found to accumulate high concentrations of LAH were investigated for their pathogenic potential in G. mellonella. Aspergillus leporis was most virulent, A. hancockii was intermediate, and A. homomorphus had very little pathogenic potential. Aspergillus leporis and A. hancockii emerged from and sporulated on dead insects, thus completing their asexual life cycles. Inoculation by injection resulted in more lethal infections than did topical inoculation, indicating A. leporis and A. hancockii were pre-adapted for insect pathogenesis but lacked an effective means to breach the insect's cuticle. All three species accumulated LAH in infected insects, with A. leporis accumulating the most. Concentrations of LAH in A. leporis were similar to those observed in the entomopathogen M. brunneum. LAH was eliminated from A. leporis through a CRISPR/Cas9-based gene knockout, and the resulting strain had reduced virulence to G. mellonella. The data indicate A. leporis and A. hancockii have considerable pathogenic potential and that LAH increases the virulence of A. leporis.

opencc-zeroJun 2023View details →

Analyses of ergot alkaloid production in Aspergillus leporis and an easD knockout and sequences for phylogenetic analyses of rugulovasine-associated genes

Ergot alkaloids are fungal specialized metabolites that are important in agriculture and serve as sources of several pharmaceuticals. Aspergillus leporis is a soil saprotroph that possesses two ergot alkaloid biosynthetic gene clusters encoding lysergic acid amide production. We identified two additional, partial biosynthetic gene clusters within the A. leporis genome containing some of the ergot alkaloid synthesis (eas) genes required to make two groups of clavine ergot alkaloids, fumigaclavines and rugulovasines. Clavines possess unique biological properties compared to lysergic acid derivatives. Bioinformatic analyses indicated the fumigaclavine cluster contained functional copies of easA, easG, easD, easM, and easN. Genes resembling easQ and easH, which are required for rugulovasine production, were identified in a separate gene cluster. The pathways encoded by these partial, or satellite, clusters would require intermediates from the previously described lysergic acid amide pathway to synthesize a product. Chemical analyses of A. leporis cultures revealed the presence of fumigaclavine A. Rugulovasine was only detected in a single sample, however, prompting a heterologous expression approach to confirm functionality of easQ and easH. An easA knockout strain of Metarhizium brunneum, which accumulates the rugulovasine precursor chanoclavine-I aldehyde, was chosen as expression host. Strains of M. brunneum expressing easQ and easH from A. leporis accumulated rugulovasine as demonstrated through mass spectrometry analysis. These data indicate that A. leporis is exceptional among fungi in having the capacity to synthesize products from three branches of the ergot alkaloid pathway and for utilizing an unusual satellite cluster approach to achieve that outcome.