The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Zennat Ferdousi - One of the best experts on this subject based on the ideXlab platform.
-
CONTROL OF Epilachna VIGINTIOCTOPUNTATA FAB. (COLEOPTERA: COCCINELLIDAE) USING SOME INDIGENOUS PLANT EXTRACTS
Journal of Life and Earth Science, 2012Co-Authors: Kamrul Islam, M Saiful Islam, Zennat FerdousiAbstract:Epilachna vigintioctopunctata is an important pest that causes considerable economic losses to many crops including egg-plants. The crude aqueous extracts of leaves from three indigenous plants namely Ricinus communis, Calotropis procera and Datura metel were used against this beetle aiming at its control under laboratory conditions. Larvicidal bioassays of the extracts showed the following order of toxicity: R. communis (LC 50 =18.40%) > C. procera (LC 50 =23.70%) > D. metel (LC 50 =29.61%). Subsequent data on some vital life-history traits were promising because the extracts significantly reduced both oviposition and egg-hatch, prolonged larval duration (P
-
control of Epilachna vigintioctopuntata fab coleoptera coccinellidae using some indigenous plant extracts
Journal of Life and Earth Science, 2012Co-Authors: Kamrul Islam, Saiful M Islam, Zennat FerdousiAbstract:Epilachna vigintioctopunctata is an important pest that causes considerable economic losses to many crops including egg-plants. The crude aqueous extracts of leaves from three indigenous plants namely Ricinus communis, Calotropis procera and Datura metel were used against this beetle aiming at its control under laboratory conditions. Larvicidal bioassays of the extracts showed the following order of toxicity: R. communis (LC 50 =18.40%) > C. procera (LC 50 =23.70%) > D. metel (LC 50 =29.61%). Subsequent data on some vital life-history traits were promising because the extracts significantly reduced both oviposition and egg-hatch, prolonged larval duration (P<0.001), and inhibited pupae formation and adult emergence (P<0.05). However, female ratio was not significantly affected by the treatments. Relevance of these findings on the control of this phytophagous species has been discussed. DOI: http://dx.doi.org/10.3329/jles.v6i0.9725 JLES 2011 6: 75-80
Thomas Eisner - One of the best experts on this subject based on the ideXlab platform.
-
antiinsectan activity of epilachnene a defensive alkaloid from pupae of mexican bean beetles Epilachna varivestis
Journal of Chemical Ecology, 2000Co-Authors: Carmen Rossini, Jerrold Meinwald, Andres Gonzalez, Jay J Farmer, Thomas EisnerAbstract:Epilachnene [(5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide], the principal component of the secretion of the pupal defensive hairs of the Mexican bean beetle (Epilachna varivestis), has antiinsectan activity. Both the R enantiomer of epilachnene, and the S enantiomer (the natural configuration of the compound), proved deterrent in a feeding bioassay with a predaceous coccinellid beetle (Harmonia axyridis). Moreover, both enantiomers proved active in a topical irritancy test with a cockroach (Periplaneta americana).
-
azamacrolides a family of alkaloids from the pupal defensive secretion of a ladybird beetle Epilachna varivestis
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Thomas Eisner, Jerrold MeinwaldAbstract:Abstract Defensive droplets from glandular hairs of the pupa of the Mexican bean beetle, Epilachna varivestis, contain a group of structurally novel alkaloids, the azamacrolides. The major constituent of this secretion, epilachnene, is shown to be (5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide. The secretion also contains an Epilachnadiene and trace amounts of three closely related components.
-
alkaloids of the mexican bean beetle Epilachna varivestis coccinellidae
Tetrahedron, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Jerrold Meinwald, Shangcheng Xu, Thomas EisnerAbstract:Abstract Two novel alkaloids, 2-(12-aminotridecyl)-pyrrolidine and its 1-(2-hydroxyethyl) derivative, are characterized from extracts of adult Mexican bean beetles. These pyrrolidines, together with a previously identified homotropane alkaloid, euphococcinine, account for 90% of the alkaloids present in this beetle. A number of piperidine derivatives are also identified as minor components. The total mixture represents the most complex bouquet of alkaloids reported hitherto from any coccinellid beetle.
Jerrold Meinwald - One of the best experts on this subject based on the ideXlab platform.
-
antiinsectan activity of epilachnene a defensive alkaloid from pupae of mexican bean beetles Epilachna varivestis
Journal of Chemical Ecology, 2000Co-Authors: Carmen Rossini, Jerrold Meinwald, Andres Gonzalez, Jay J Farmer, Thomas EisnerAbstract:Epilachnene [(5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide], the principal component of the secretion of the pupal defensive hairs of the Mexican bean beetle (Epilachna varivestis), has antiinsectan activity. Both the R enantiomer of epilachnene, and the S enantiomer (the natural configuration of the compound), proved deterrent in a feeding bioassay with a predaceous coccinellid beetle (Harmonia axyridis). Moreover, both enantiomers proved active in a topical irritancy test with a cockroach (Periplaneta americana).
-
synthesis and absolute configuration of 2 12 aminotridecyl pyrrolidine a defensive alkaloid from the mexican bean beetle Epilachna varivestis
Tetrahedron, 1996Co-Authors: Athula B Attygalle, Shangcheng Xu, Viqar U Ahmad, Jerrold MeinwaldAbstract:Abstract The synthesis of 2-(12′-aminotridecyl)-pyrrolidine ( 1 ), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis , is described. The (2 S ,12′ R ) configuration is assigned to this alkaloid by comparing the 1 H NMR spectrum of its ( S )-MTPA derivative with that of ( R )- and ( S )-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.
-
Synthesis and absolute configuration of 2-(12′-aminotridecyl)-pyrrolidine, a defensive alkaloid from the Mexican bean beetle, Epilachna varivestis
Tetrahedron, 1996Co-Authors: Athula B Attygalle, Shangcheng Xu, Viqar U Ahmad, Jerrold MeinwaldAbstract:Abstract The synthesis of 2-(12′-aminotridecyl)-pyrrolidine ( 1 ), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis , is described. The (2 S ,12′ R ) configuration is assigned to this alkaloid by comparing the 1 H NMR spectrum of its ( S )-MTPA derivative with that of ( R )- and ( S )-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.
-
azamacrolides a family of alkaloids from the pupal defensive secretion of a ladybird beetle Epilachna varivestis
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Thomas Eisner, Jerrold MeinwaldAbstract:Abstract Defensive droplets from glandular hairs of the pupa of the Mexican bean beetle, Epilachna varivestis, contain a group of structurally novel alkaloids, the azamacrolides. The major constituent of this secretion, epilachnene, is shown to be (5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide. The secretion also contains an Epilachnadiene and trace amounts of three closely related components.
-
alkaloids of the mexican bean beetle Epilachna varivestis coccinellidae
Tetrahedron, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Jerrold Meinwald, Shangcheng Xu, Thomas EisnerAbstract:Abstract Two novel alkaloids, 2-(12-aminotridecyl)-pyrrolidine and its 1-(2-hydroxyethyl) derivative, are characterized from extracts of adult Mexican bean beetles. These pyrrolidines, together with a previously identified homotropane alkaloid, euphococcinine, account for 90% of the alkaloids present in this beetle. A number of piperidine derivatives are also identified as minor components. The total mixture represents the most complex bouquet of alkaloids reported hitherto from any coccinellid beetle.
Athula B Attygalle - One of the best experts on this subject based on the ideXlab platform.
-
synthesis and absolute configuration of two defensive alkaloids from the mexican bean beetle Epilachna varivestis
Tetrahedron Letters, 1997Co-Authors: Athula B Attygalle, Ferrold MeinwaldAbstract:Abstract Syntheses of (2 S ,12′ R )-2-(12′-aminotridecyl)-pyrrolidine ( 1 ) and (2 S ,12′ R )-1-(2″-hydroxyethyl)-2-(12′-aminotridecyl)-pyrrolidine ( 2 ), two defensive alkaloids recently isolated from the Mexican bean beetle, Epilachna varivestis , are described. By a comparison of 1 H NMR data of MTPA derivatives of natural alkaloid 2 with those of the synthetic standard, we confirm the (2 S ,12′ R ) configuration previously suggested for this alkaloid. Further support of these assignments was provided by the synthesis and 1 H NMR investigation of (2 S ,12′ S )- 1 , (2 S ,12′ S )- 2 , and their MTPA derivatives.
-
Synthesis and absolute configuration of 2-(12′-aminotridecyl)-pyrrolidine, a defensive alkaloid from the Mexican bean beetle, Epilachna varivestis
Tetrahedron, 1996Co-Authors: Athula B Attygalle, Shangcheng Xu, Viqar U Ahmad, Jerrold MeinwaldAbstract:Abstract The synthesis of 2-(12′-aminotridecyl)-pyrrolidine ( 1 ), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis , is described. The (2 S ,12′ R ) configuration is assigned to this alkaloid by comparing the 1 H NMR spectrum of its ( S )-MTPA derivative with that of ( R )- and ( S )-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.
-
synthesis and absolute configuration of 2 12 aminotridecyl pyrrolidine a defensive alkaloid from the mexican bean beetle Epilachna varivestis
Tetrahedron, 1996Co-Authors: Athula B Attygalle, Shangcheng Xu, Viqar U Ahmad, Jerrold MeinwaldAbstract:Abstract The synthesis of 2-(12′-aminotridecyl)-pyrrolidine ( 1 ), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis , is described. The (2 S ,12′ R ) configuration is assigned to this alkaloid by comparing the 1 H NMR spectrum of its ( S )-MTPA derivative with that of ( R )- and ( S )-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.
-
azamacrolides a family of alkaloids from the pupal defensive secretion of a ladybird beetle Epilachna varivestis
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Thomas Eisner, Jerrold MeinwaldAbstract:Abstract Defensive droplets from glandular hairs of the pupa of the Mexican bean beetle, Epilachna varivestis, contain a group of structurally novel alkaloids, the azamacrolides. The major constituent of this secretion, epilachnene, is shown to be (5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide. The secretion also contains an Epilachnadiene and trace amounts of three closely related components.
-
alkaloids of the mexican bean beetle Epilachna varivestis coccinellidae
Tetrahedron, 1993Co-Authors: Athula B Attygalle, Kevin D Mccormick, Curtis L Blankespoor, Jerrold Meinwald, Shangcheng Xu, Thomas EisnerAbstract:Abstract Two novel alkaloids, 2-(12-aminotridecyl)-pyrrolidine and its 1-(2-hydroxyethyl) derivative, are characterized from extracts of adult Mexican bean beetles. These pyrrolidines, together with a previously identified homotropane alkaloid, euphococcinine, account for 90% of the alkaloids present in this beetle. A number of piperidine derivatives are also identified as minor components. The total mixture represents the most complex bouquet of alkaloids reported hitherto from any coccinellid beetle.
H Schmutterer - One of the best experts on this subject based on the ideXlab platform.
-
die wirkung von rohpressaften und rohextrakten aus ajuga arten auf frasaktivitat und metamorphose von Epilachna varivestis muls
Journal of Applied Entomology, 2009Co-Authors: H Schmutterer, Gisela TervoorenAbstract:The effect of squeezed juices and crude extracts of Ajuga species on feeding activity and metamorphosis of Epilachna varivestis (Col., Coccinellidae) The effect of fresh, squeezed plant juices and that of crude extracts from dried parts of Ajuga reptans and A. remota on the feeding activity and metamorphosis of Epilachna varivestis was investigated by means of various testing methods. Squeezed plant juices and crude plant extracts cause a strong antifeedant effect. The causal agents are most probably ajugarins, at least in case of A. remota. Furthermore, the metamorphosis is strongly influenced by the extracts, leading to high larval and pupal mortalities, the appearance of pupal-adult specimens and of beetles showing more or less deformed wings. The growth-regulating effect is presumedly caused by ecdysoids, primarily ecdysterone. Zusammenfassung Die Wirkung von Pressaften aus frischen und von Rohextrakten aus getrockneten Teilen von Ajuga reptans und A. remota auf die Frasaktivitat und Metamorphose von Epilachna varivestis wurde mit Hilfe verschiedener Testmethoden untersucht. Pressafte und Rohextrakte bewirken eine deutliche Frashemmung, die zumindest bei A. remota wahrscheinlich auf Ajugarine zuruckgefuhrt werden konnen. Auserdem wird die Metamorphose stark beeinflust, was zu hoher Larven- und Puppenmortalitat sowie zur Entstehung sog. pupal-adulter Tiere und zu Kafern mit mehr oder weniger stark deformierten Flugeln fuhrt. Die metamorphosestorende Wirkung ist mit groser Wahrscheinlichkeit auf die in den Ajuga-Arten enthaltenen Ecdysoide, insbesondere das Ecdysteron zuruckzufuhren.
-
Die Wirkung von Rohpreßsäften und Rohextrakten aus Ajuga‐Arten auf Fraßaktivität und Metamorphose von Epilachna varivestis Muls
Journal of Applied Entomology, 2009Co-Authors: H Schmutterer, Gisela TervoorenAbstract:The effect of squeezed juices and crude extracts of Ajuga species on feeding activity and metamorphosis of Epilachna varivestis (Col., Coccinellidae) The effect of fresh, squeezed plant juices and that of crude extracts from dried parts of Ajuga reptans and A. remota on the feeding activity and metamorphosis of Epilachna varivestis was investigated by means of various testing methods. Squeezed plant juices and crude plant extracts cause a strong antifeedant effect. The causal agents are most probably ajugarins, at least in case of A. remota. Furthermore, the metamorphosis is strongly influenced by the extracts, leading to high larval and pupal mortalities, the appearance of pupal-adult specimens and of beetles showing more or less deformed wings. The growth-regulating effect is presumedly caused by ecdysoids, primarily ecdysterone. Zusammenfassung Die Wirkung von Pressaften aus frischen und von Rohextrakten aus getrockneten Teilen von Ajuga reptans und A. remota auf die Frasaktivitat und Metamorphose von Epilachna varivestis wurde mit Hilfe verschiedener Testmethoden untersucht. Pressafte und Rohextrakte bewirken eine deutliche Frashemmung, die zumindest bei A. remota wahrscheinlich auf Ajugarine zuruckgefuhrt werden konnen. Auserdem wird die Metamorphose stark beeinflust, was zu hoher Larven- und Puppenmortalitat sowie zur Entstehung sog. pupal-adulter Tiere und zu Kafern mit mehr oder weniger stark deformierten Flugeln fuhrt. Die metamorphosestorende Wirkung ist mit groser Wahrscheinlichkeit auf die in den Ajuga-Arten enthaltenen Ecdysoide, insbesondere das Ecdysteron zuruckzufuhren.
-
zur wirkung einiger reinfraktionen aus samen von azadirachta indica auf frasaktivitat und metamorphose von Epilachna varivestis col coccinellidae
Journal of Applied Entomology, 2009Co-Authors: H Schmutterer, H RemboldAbstract:Effects of some pure fractions of extracts from neem (Azadirachta indica) seeds on feeding activity and metamorphosis of Epilachna varivestis (Col. Coccinellidae) In a number of publications of various authors on the ingredients of neem tree (Azadirachta indica) seeds only azadirachtin was mentioned as an effective growth regulator in insects of various orders. This triterpenoid was also identified as a potent phagorepellent and sterilant. In the present investigation some fractions of extracts from neem seeds of West African origin (Togo) were purified. Four finally obtained pure fractions showed strong to very strong growth disruption effects in Epilachna varivestis, a fifthone was somewhat less active. After uptake of the neem seed ingredients by feeding on treated bean leaves various more-or-less typical symptoms appeared in fourth instar larvae. They can be described as follows: Under the influence of fractions 18-79a I and 18-79a II the larvae gradually shriveled until they died; fraction 18-79b I caused blackish legs in the shriveling test insects. After the uptake of fractions 18-80b and 18-80d reddish-brown spots appeared in the dorso-lateral zones of the thorax. The larvae showing this type of symptoms were very large and died not before about three weeks after appearance of such spots. Only fraction 18-79a I showed obvious phagorepellent properties mainly during the first day of the so-called “petri dish test”. Fractions 18-79a I, 18-79a II and 18-80b also prevented moulting from the 3rd to the 4th instar larva even in very low concentrations. After uptake of fraction 18-79b I and 18-80d the majority of 3rd instar larvae was able to moult but the resulting 4the instar larvae refused to feed on untreated bean leaves and died some days afterwards. Zusammenfassung In bisherigen Veroffentlichungen uber Inhaltsstoffe aus Neem-(Azadirachta indica-) Samen wurde lediglich das Triterpenoid Azadirachtin als metamorphosestorender Stoff bei Insekten verschiedener Ordnungen erwahnt. Gleichzeitig wurde es als sehr wirksames Phagorepellent identifiziert. Eine von laufenden Biotesten begleitete Fraktionierung der Extrakte aus Neem-Samen westafrikanischer Herkunft ergab, das insgesamt vier stark bis sehr stark und ein weiterer, schwacher wirksamer Inhaltsstoff vorhanden sind, die tiefgreifende Einflusse auf die Metamorphose von Epilachna varivestis ausuben konnen. An Viertlarven treten nach oraler Aufnahme der Wirkstoffe unterschiedliche, mehr oder weniger typische Symptome auf, die sich in drei Gruppen einteilen lassen: Bei den Reinfraktionen 18-79a I und 18-79a II schrumpfen die Testtiere allmahlich zusammen, bei 18-79b I werden vor dem Einschrumpfen des Korpers die Beine schwarz. Bei den Fraktionen 18-80b und 18-80d treten auf dem Thorax 1–4 rotbraune Flecke auf und die Larven sterben erst nach mehreren Wochen ab. Lediglich die Fraktion 18-79a I zeigt eine deutliche frasabschreckende Wirkung, besonders wahrend des 1. Versuchstages. Die Fraktionen 18-79a I, 18-79a II und 18-80b verhindern selbst in sehr niedriger Konzentration die Hautung von der L3 zur L4. Die Reinfraktionen 18-79b I und 18-80d konnen die Hautung zwar bei den meisten L3 nicht verhindern, doch sterben die L4 dann wenige Tage spater, meist ohne vorher noch Futter aufgenommen zu haben.
