Insecticidal Alkaloids against Drosophila melanogaster from Nuphar japonicum DC.

Abstract

In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, MeOH extract of rhizomes of Nuphar japonicum DC. was found to give an insecticidal activity against larvae of Drosophila melanogaster Meigen. Four alkaloids, (−)-7-epi-deoxynupharidine (1), (−)-castoramine (2), (−)-nupharolutine (3), and (−)-nupharmine (4), were isolated by bioassy-guided fractionation from the extract. Insecticidal activity against larvae of D. melanogaster was demonstrated; 2 and 1 showed LC50 values of 1.00 and 4.33 μmol/mL of diet concentration, respectively. Acute toxicity against adults of D. melanogaster was also found; 1 had the most potent activity, with an LD50 value of 0.86 μg/adult. 1, 2, and 3 caused acetylcholinesterase inhibitions, at 0.5 mmol/L, of 99.6, 65.0, and 59.7%, respectively; however, 4 had only slight activity in this study. Therefore, 1 and 2 were identified as insecticidal compounds from rhizomes of N. japonicum DC. Structure−bioactivity relationship study indicated the importance of the position of the hydroxyl group and the piperizine skeleton for enhanced activity. Keywords: Nuphar japonicum DC.; Nymphaeaceae; rhizomes; Drosophila melanogaster Meigen; sesquiterpene alkaloids; (−)-7-epi-deoxynupharidine; (−)-castoramine; (−)-nupharolutine; (−)-nuphamine; insecticidal activity; structure−activity relationship

Insecticidal Effect and Chemical Composition of the Volatile Oil from Bergenia ligulata

“…20 Adults from culture bottles were iced to stop their movement and treated on their abdomens with each of the test compounds at doses of 20, 2, and 0.2 μg/adult in 0.5 μL of acetone with a 10 μL microsyringe. Controls were treated with 0.5 μL of acetone.…”

Insecticidal compounds from Evodia rutaecarpa against Drosophila melanogaster

“…The bioassay for insecticidal activity against larvae of D melanogaster was carried out as follows 1–8, 13. Four concentrations of test compounds (1.40, 0.84, 0.28 and 0.11 µmol ml −1 diet) were used for determining LC 50 values.…”

“…Acute toxicity was determined by topical application to adults of D melanogaster 4–8. Adults were chilled on ice to stop their movement, and treated on their abdomens with each of the test compounds at doses of 10, 7, 5, 3 and 1 µg in 0.5 µl of acetone with a 10 µl microsyringe.…”

“…In our search for new naturally occurring insecticidal compounds, we have studied Chinese crude drugs with a history of safe use as medicines 1–8. In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, the MeOH extract of the fruits of Evodia rutaecarpa Benth was found to exhibit insecticidal activity against larvae of Drosophila melanogaster Meigen.…”

Étude du potentiel bioactif de la Brasenia schreberi /

“…Une approche efficace dans la recherche de composés d'intérêt biopharmaceutique consiste en un fractionnement guidé par la bioactivité [32]. Suite à un échantillonnage, la première étape précédant l'extraction de composés chimiques dans une plante aquatique de la famille des Nymphacées est habituellement un séchage à l'air [33,34] [44,45]. Ces informations structurales sont indispensables à l'élucidation de la structure chimique d'un composé.…”