Fagodisuasión de un extracto de ruda (Ruta chalepensis, Rutaceae) y sus particiones sobre larvas de Hypsipyla grandella (Lepidoptera: Pyralidae)

Phagodeterrence by a crude extract of common rue (Ruta chalepensis, Rutaceae) and its partitions on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae. Hypsipyla grandella (Zeller) larva is maybe the main forest pest in Latin America and the Caribbean, as it bores into the main shoot of trees providing precious woods, such as mahoganies (Swietenia spp.) and cedars (Cedrela spp.). In the search for a preventative method for managing it, the crude leaf extract of common rue (Ruta chalepensis L.), as well as four partitions thereof (water, hexane, dichlorometane, and ethyl acetate), were tested for phagodeterrence. Laboratory bioassays involved increasing concentrations of the crude extract (0.1, 0.32, 1.0, 3.20 and 10.0%w/v) as well as each one of the partitions (in accordance to the yield obtained from the partitioning process), plus rutin, a flavone glycosid. A randomized complete block design, with four replicates, was used. H. grandella instar III larvae were exposed for 24 h to cedar (Cedrela odorata) leaf discs dipped into the respective treatment, after which disc consumption was measured. Strong phagodeterrence was detected at concentrations as low as 0.32 and 0.074%w/v for the crude extract and the hexane partitions, respectively; the ethyl acetate (0.24%w/v) and the water partition (for all of its concentrations), as well as the rutin (starting at 0.064%w/v), caused phagodeterrence, too. Moreover, the crude extract was submitted to a phytochemical screening by means of a number of qualitative tests, to determine possible metabolites causing phagodeterrence, the most important being alkaloids, triterpenes, coumarins and rutin. A particular phytochemical screening was carried out for the hexane partition, which was the most active. Rev. Biol. Trop. 58 (1): 1-14. Epub 2010 March 01.

La larva de Hypsipyla grandella (Zeller) es quizás la principal plaga forestal en América Latina y el Caribe, por perforar el brote principal de árboles de maderas reciosas, como caobas (Swietenia spp.) y cedros (Cedrela spp.). En la búsqueda de un método preventivo para su manejo, se estudió la actividad fagodisuasiva del extracto crudo y de cuatro particiones fitoquímicas (agua, hexano, diclorometano y acetato de etilo) del follaje de ruda (Ruta chalepensis L.). Se realizaron bioensayos de laboratorio con concentraciones crecientes del extracto crudo (0.1; 0.32; 1.0; 3.20 y 10.0%m/v) y con cada una de las particiones (según el rendimiento del proceso de particionamiento), así como con el glicósido flavónico rutina. Para ello se empleó un diseño de bloques completamente al azar, con cuatro repeticiones y se expusieron larvas de instar III de H. grandella a discos de cedro (Cedrela odorata) impregnados con el respectivo tratamiento, por 24h. Se midió el porcentaje de consumo de cada disco. Hubo un fuerte efecto fagodisuasivo en el extracto crudo y en la partición hexano, a concentraciones tan bajas como 0.32% y 0.074% m/v, respectivamente; las particiones de acetato de etilo (0.24%m/v) y la acuosa (en todas sus concentraciones), así como la rutina (a partir del 0.064%m/v) también causaron fagodisuasión. Además, se realizó un tamizaje fitoquímico del extracto crudo, utilizando varias pruebas cualitativas para detectar la presencia de los principales grupos de metabolitos secundarios, entre los cuales los más importantes fueron alcaloides, triterpenos, cumarinas y la rutina. Asimismo, se realizó una marcha fitoquímica a la partición hexano, por ser la más activa.

Caracterização química dos raticidas granulados comercializados na cidade de Belém-Pará / Chemical identification of granulated rodenticides market in Belém-Pará

Objetivo: caracterizar a composição química dos raticidas granulados comercializados na região metropolitana de Belém - Pará. Método: triagem por cromatografia em camada delgada de 120 amostras de raticidas emfeiras livres e outros estabelecimentos comerciais na região metropolitana de Relém. Resultado; amostras analisadas foram positivas para carbamatos, 25% para organofosforados e 5% para cum encontradas 15% da associação carbamato e organofosforado. Conclusão: os carbamatos foram os mais encontrados (55%).

Objective: this work aimed the chemical identification of granulated rodenticides market in Belem-Para, for help in the diagnosis and treatment of the intoxicated patients. Method: screening by thin layer chromatography of 120 samples of granulated rodenticides acquired commercial establishments located in the metropolitan region of Belem-Para. Results: 55% of the analyzed samples were positive for carbamate, 25% for organophosphates and, 5% for coumarins. Were founds 15% of carbamate and organophosphate associations. Conclusion: the treatmen and laboratorial evaluation of poisoning for those compounds require differentiated procedures.