Insecticidal activity of Piper tuberculatum Jacq. extracts: synergistic interaction of piperamides

Abstract

1 The insecticidal activity of the neotropical pepper Piper tuberculatum Jacq. and its isolated piperamides was studied. Bioassays with the mosquito Aedes atropalpus L. assessed the relative toxicity of the whole extract of Piper tuberculatum and four of the piperamides, which were isolated and identified, then prepared synthetically. 2 The results confirm that P. tuberculatum leaf extracts are as effective as black pepper seed extract and provide an alternative pepper insecticide from a more convenient source, the leaves. 3 Experiments with piperamides showed that the tertiary and quaternary mixtures have greater-than-additive toxicity compared to single compounds or binary mixtures. One of the four amide compounds, 4,5-dihydropiperlonguminine, was the most acutely toxic in mosquito larvae bioassays. 4 A study of piperamide levels from different P. tuberculatum populations in Costa Rica determined that they were relatively homogeneous. Piper tuberculatum from only one of the five sites had higher levels of one piperamide, 4,5-dihydropiperine, in both leaf and stem parts. One explanation for differences in the amide concentrations between populations is that one site is ecologically unique compared to the other four.

Does plant apparency matter? Thirty years of data provide limited support but reveal clear patterns of the effects of plant chemistry on herbivores

“…New Phytologist synergistic effects of plant chemistry on herbivores in other plant species (Calcagno et al, 2002;Scott et al, 2002;Dyer et al, 2003;Richards et al, 2010Richards et al, , 2012. If most secondary compounds act in a synergistic fashion, then the results reported here from 30 yr of data may not reflect the true effects that secondary metabolites have on herbivores.…”

Controle alternativo do Brevicoryne brassicae (Hemiptera: Aphididae) com extratos de diferentes espécies de plantas

“…A variedade de atividades biológicas exibida pela piperina é bastante ampla. Essas substâncias agem como neurotoxinas e afetam as funções do sistema nervoso central, causando rápida paralisia do inseto (Scott et al, 2002).…”

Actividad inhibitoria de plantas in vitro de Drosera capillaris sobre Mycobacterium tuberculosis

“…Al respecto, estudios realizados sobre la actividad biocida de extractos crudos comparando con sustancias puras (piperamidas), obtenidas de Piper tuberculatum, han demostrado un efecto más potente del extracto crudo sobre Aedes atropalpus (Scott et al 2002) y Anticarsia gemmatalis (Navickiene et al 2007), respectivamente, que cuando se utilizaron sustancias puras, aún en combinaciones binarias, terciarias y cuaternarias.…”