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Ralph A. Saporito - One of the best experts on this subject based on the ideXlab platform.
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Piperidine Alkaloids from fire ants are not sequestered by the green and black poison frog (Dendrobates auratus)
Chemoecology, 2021Co-Authors: Ian Davison, Ralph A. Saporito, Lisa M. Schulte, Kyle SummersAbstract:Neotropical poison frogs possess alkaloid-based antipredator defenses which they sequester from a diet of arthropods such as oribatid mites and myrmicine ants. Alkaloid sequestration is still poorly understood and although several studies have examined its uptake, most experiments directly feed Alkaloids to the frogs. Here, we examined the alkaloid uptake system in the poison frog species Dendrobates auratus by feeding it an alkaloid-containing prey item, the red imported fire ant Solenopsis invicta (Formicidae, Myrmicinae). Captive bred frogs were either fed live ants or fruit flies dusted with powdered ants for 4 months. Using GC–MS, we confirm that S. invicta contain previously described piperidine Alkaloids known as solenopsins; however, none of these piperidine Alkaloids was detected in the skin of D. auratus , suggesting the frogs are incapable of sequestering solenopsins from S. invicta . It is possible that D. auratus are unable to sequester fire ant piperidines due to their long hydrocarbon side chains, a feature that makes them structurally different than most known Alkaloids in poison frogs.
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Dietary Alkaloid Sequestration in a Poison Frog: An Experimental Test of Alkaloid Uptake in Melanophryniscus stelzneri (Bufonidae)
Journal of Chemical Ecology, 2013Co-Authors: Maggie M. Hantak, Taran Grant, Sherri Reinsch, Dale Mcginnity, Marjorie Loring, Naoki Toyooka, Ralph A. SaporitoAbstract:Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as ‘poison frogs,’ form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester Alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive Alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the Alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the Alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained Alkaloids, whereas those of all control frogs lacked Alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain Alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary sources.
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Geographic and Seasonal Variation in Alkaloid-Based Chemical Defenses of Dendrobates pumilio from Bocas del Toro, Panama
Journal of Chemical Ecology, 2006Co-Authors: Ralph A. Saporito, Maureen A. Donnelly, H. Martin Garraffo, Thomas F. Spande, John W. DalyAbstract:Poison frogs contain an alkaloid-based chemical defense that is derived from a diet of certain alkaloid-containing arthropods, which include mites, ants, beetles, and millipedes. Variation in population-level alkaloid profiles among species has been documented, and more than 800 different Alkaloids have been identified. In the present study, we examine individual alkaloid variation in the dendrobatid poison frog Dendrobates pumilio among seven populations and between two seasons on Isla Bastimentos, located in the Bocas del Toro archipelago of Panama. Alkaloid profiles vary among populations and between seasons, illustrating that chemical defense in this species can vary on a small spatial and temporal scale. Alkaloid variation among populations is marginally correlated with geographic distance, and close populations have profiles more similar to each other than to distant populations. Individuals within populations also vary in alkaloid profiles. Differences are attributed to both spatial and temporal variations in the availability of alkaloid-containing arthropods. Many of the Alkaloids present in the skin of D. pumilio appear likely to be of ant origin, supporting the importance of myrmecophagy in chemical defense among poison frogs. However, a variety of frog skin Alkaloids was recently detected in mites, suggesting that mites may also play an important role in chemical defense.
Dietrich Ober - One of the best experts on this subject based on the ideXlab platform.
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Independent Recruitment of a Flavin-Dependent Monooxygenase for Safe Accumulation of Sequestered Pyrrolizidine Alkaloids in Grasshoppers and Moths
2013Co-Authors: Linzhu Wang, Till Beuerle, James Timbilla, Dietrich OberAbstract:Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine Alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine Alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine Alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine Alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine Alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavindependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine Alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequenc
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Independent recruitment of a flavin-dependent monooxygenase for safe accumulation of sequestered pyrrolizidine Alkaloids in grasshoppers and moths.
PLoS ONE, 2012Co-Authors: Linzhu Wang, Till Beuerle, James Timbilla, Dietrich OberAbstract:Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine Alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine Alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine Alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine Alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine Alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavin-dependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine Alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequence identity between the three Z. variegatus sequences this ability to N-oxygenize pyrrolizidine Alkaloids is interpreted as a relict of a former bifunctional ancestor gene of which one of the gene copies optimized this activity for the specific adaptation to pyrrolizidine alkaloid containing food plants.
Linzhu Wang - One of the best experts on this subject based on the ideXlab platform.
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Independent Recruitment of a Flavin-Dependent Monooxygenase for Safe Accumulation of Sequestered Pyrrolizidine Alkaloids in Grasshoppers and Moths
2013Co-Authors: Linzhu Wang, Till Beuerle, James Timbilla, Dietrich OberAbstract:Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine Alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine Alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine Alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine Alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine Alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavindependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine Alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequenc
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Independent recruitment of a flavin-dependent monooxygenase for safe accumulation of sequestered pyrrolizidine Alkaloids in grasshoppers and moths.
PLoS ONE, 2012Co-Authors: Linzhu Wang, Till Beuerle, James Timbilla, Dietrich OberAbstract:Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine Alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine Alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine Alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine Alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine Alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavin-dependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine Alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequence identity between the three Z. variegatus sequences this ability to N-oxygenize pyrrolizidine Alkaloids is interpreted as a relict of a former bifunctional ancestor gene of which one of the gene copies optimized this activity for the specific adaptation to pyrrolizidine alkaloid containing food plants.
Hulcová Daniela - One of the best experts on this subject based on the ideXlab platform.
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Biological activity of Alkaloids from Narcissus pseudonarcissus L. cv. Dutch Master (Amaryllidaceae)
Univerzita Karlova Farmaceutická fakulta v Hradci Králové, 2019Co-Authors: Hulcová DanielaAbstract:4. Abstrakt Univerzita Karlova v Praze, Farmaceutická fakulta v Hradci Králové Katedra farmaceutické botaniky Kandidát: Mgr. Daniela Hulcová Školitel: Doc. Ing. Lucie Cahlíková, Ph.D. Název disertační práce: Biologická aktivita alkaloidů Narcissus pseudonarcissus L. cv. Dutch Master (Amaryllidaceae) Klíčková slova: Narcissus pseudonarcissus L. cv. Dutch Master, Amaryllidaceae, alkaloidy, AChE, BuChE, POP, GSK-3β, biologická aktivita. Cibule z Narcissus pseudonarcissus L. cv. Dutch Master z čeledi Amaryllidaceae byly spolu s dalšími druhy rodu Narcissus podrobeny bio-guided studii. Tato studie hodnotila sumární alkaloidní extrakty z pohledu jejich cholinesterasové inhibiční aktivity. Navíc byly provedeny podrobné GC-MS analýzy za účelem identifikace jednotlivých složek. Na základě získaných výsledků byl vybrán Narcissus pseudonarcissus L. cv. Dutch Master jako vhodný zdroj širokého spektra amarylkovitých alkaloidů. Čerstvé cibule tohoto narcisu byly extrahovány ethanolem a sumární extrakt byl separován na jednotlivé frakce pomocí sloupcové chromatografie za využití oxidu hlinitého a silikagelu jako stacionární fáze. Následně byla provedena stupňovitá eluce, kde mobilní fází byla směs různých poměrů benzín - chloroform a chloroform - ethanol. Některé frakce bylo nutno opakovaně rozdělit pomocí sloupcové...5. Abstract Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Mgr. Daniela Hulcová Supervisor: Doc. Ing. Lucie Cahlíková, Ph.D. Title of Doctoral Thesis: Biological activity of Alkaloids Narcissus pseudonarcissus L. cv. Dutch Master (Amaryllidaceae) Keywords: Narcissus pseudonarcissus L. cv. Dutch Master, Amaryllidaceae, Alkaloids, AChE, BuChE, POP, GSK-3β, biological activity. Bulbs of Narcissus pseudonarcissus L. cv. the Dutch Master of the Amaryllidaceae family, along with other species of the genus Narcissus, was subjected to a bio-guided study. This study evaluated summary alkaloid extracts using spectrophotometric Ellmans method and GC-MS analysis as a possible source of biologically active Amaryllidaceae Alkaloids. Narcissus pseudonarcissus L. cv. Dutch Master was selected as a suitable source for isolation of Alkaloids. The fresh bulbs of this daffodil were extracted with ethanol and the crude extract was separated into individual fractions by column chromatography using alumina and silica gel as a stationary phase. Subsequently a stepwise elution was performed, where the mobile phase was a mixture of different ratios of petrol - chloroform and chloroform - ethanol. Some fractions had to be repeatedly partitioned by column...Katedra farmaceutické botanikyDepartment of Pharmaceutical BotanyFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov
Philippe Guerre - One of the best experts on this subject based on the ideXlab platform.
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Ergot Alkaloids Produced by Endophytic Fungi of the Genus Epichloë
Toxins, 2015Co-Authors: Philippe GuerreAbstract:The development of fungal endophytes of the genus Epichloe in grasses results in the production of different groups of Alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot Alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene Alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline Alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot Alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot Alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot Alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.
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Ergot Alkaloids Produced by Endophytic Fungi of the Genus Epichloë
MDPI AG, 2015Co-Authors: Philippe GuerreAbstract:The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of Alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot Alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene Alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline Alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot Alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot Alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot Alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity
