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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.
Yuepeng Han - One of the best experts on this subject based on the ideXlab platform.
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analysis of isoquinoline Alkaloid composition and wound induced variation in nelumbo using hplc ms ms
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Xianbao Deng, Lingping Zhu, Ting Fang, Sornkanok Vimolmangkang, Dong Yang, Collins Ogutu, Yanling Liu, Yuepeng HanAbstract:Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the Alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline Alkaloids, whereas petioles and rhizomes contain trace amounts of Alkaloids. Wide variation of Alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, Alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type Alkaloids, respectively. Bisbenzylisoquinoline-type Alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific Alkaloids in lotus leaves.
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Analysis of Isoquinoline Alkaloid Composition and Wound-Induced Variation in Nelumbo Using HPLC-MS/MS
2016Co-Authors: Xianbao Deng, Lingping Zhu, Ting Fang, Sornkanok Vimolmangkang, Dong Yang, Collins Ogutu, Yanling Liu, Yuepeng HanAbstract:Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the Alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline Alkaloids, whereas petioles and rhizomes contain trace amounts of Alkaloids. Wide variation of Alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, Alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type Alkaloids, respectively. Bisbenzylisoquinoline-type Alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific Alkaloids in lotus leaves
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.
D. R. Gardner - One of the best experts on this subject based on the ideXlab platform.
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A Functional Explanation for Patterns of Norditerpenoid Alkaloid Levels in Tall Larkspur (Delphinium barbeyi)
Journal of Chemical Ecology, 2000Co-Authors: M. H. Ralphs, D. R. GardnerAbstract:Concentrations of norditerpenoid Alkaloids vary among larkspur ( Delphinium ) species, locations, and years, but environmental stresses seem to have little effect on Alkaloid levels. There is a need for a functional hypothesis of Alkaloid synthesis and metabolism to explain the observed trends in concentration and to predict the toxicity of larkspur populations. This study was replicated at two locations over two years in the mountains of central Utah. Ten tall larkspur ( D. barbeyi ) plants were marked at each location, and a single stalk was harvested from each plant at weekly intervals throughout the growing season. Concentrations of toxic and total Alkaloids were measured by Fourier-transformed infrared spectroscopy (FTIR), and Alkaloid pools were calculated by multiplying the Alkaloid concentration by the dry weight of the plant to determine the amount of Alkaloids in the stalk. Alkaloid pools in the stalks increased for the first three weeks, leveled off, and then declined to low levels as the plants began to senesce. Concentrations of Alkaloids declined through the season, as the Alkaloids were diluted in the increasing biomass as the plants grew. These patterns will be used to predict potential toxicity of larkspur populations.
Xianbao Deng - One of the best experts on this subject based on the ideXlab platform.
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analysis of isoquinoline Alkaloid composition and wound induced variation in nelumbo using hplc ms ms
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Xianbao Deng, Lingping Zhu, Ting Fang, Sornkanok Vimolmangkang, Dong Yang, Collins Ogutu, Yanling Liu, Yuepeng HanAbstract:Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the Alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline Alkaloids, whereas petioles and rhizomes contain trace amounts of Alkaloids. Wide variation of Alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, Alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type Alkaloids, respectively. Bisbenzylisoquinoline-type Alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific Alkaloids in lotus leaves.
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Analysis of Isoquinoline Alkaloid Composition and Wound-Induced Variation in Nelumbo Using HPLC-MS/MS
2016Co-Authors: Xianbao Deng, Lingping Zhu, Ting Fang, Sornkanok Vimolmangkang, Dong Yang, Collins Ogutu, Yanling Liu, Yuepeng HanAbstract:Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the Alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline Alkaloids, whereas petioles and rhizomes contain trace amounts of Alkaloids. Wide variation of Alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, Alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type Alkaloids, respectively. Bisbenzylisoquinoline-type Alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific Alkaloids in lotus leaves
