| Autor: |
Morais FS; Instituto Federal de Ciência e Tecnologia do Amazonas (IFAM), Itacoatiara, Amazonas 69109899, Brazil., Canuto KM; Embrapa Agroindústria Tropical, Fortaleza, Ceará, Brazil., Ribeiro PRV; Embrapa Agroindústria Tropical, Fortaleza, Ceará, Brazil., Silva AB; Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Ceará, Brazil., Pessoa ODL; Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Ceará, Brazil., Freitas CDT; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil., Bezerra EA; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil., Gonçalves JFC; Laboratório de Fisiologia e Bioquímica de Plantas, Instituto Nacional de Pesquisa da Amazônia - INPA, Manaus, AM, Brazil., Souza DP; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil., Sousa BF; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil., Silva AFB; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil., Ramos MV; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil. |
| Abstrakt: |
Vigna unguiculata is an important source of proteins and energy for humans and animals. However, postharvest losses caused by Callosobruchus maculatus can reach from 20 to 100% of stored seeds. In this study, the insecticide potential of compounds extracted from Himatanthus drasticus latex was assessed. The latex was extracted with ethanol (70%) and then partitioned through sequential use of hexane and chloroform. These fractions were investigated by chromatography to determine their chemical composition. Plumieride, identified in a hydroalcoholic subfraction, was tested for insecticidal activity against C. maculatus . The ethanolic fraction (LC 50 = 0.109; LC 90 = 0.106%) and the plumieride (LC 50 = 0.166; LC 90 = 0.167%) were lethal to larvae. Plumieride (0.25%) delayed larval development, and mortality reached 100%. Its inhibitory action on intestinal α-amylase from larvae was higher (89.12%) than that of acarbose (63.82%). Plumieride (0.1%) inhibited the enzyme α-amylase in vivo in the larval intestine. This result was confirmed by a zymogram test performed by SDS-PAGE when the enzyme electrophoresed on gel copolymerized with starch. When spread on seeds, the hydroalcoholic fraction (1.0%) reduced infestation. The loss of seed mass was 5.26% compared to the control (44.97%). The results confirm the effect of latex compounds in protecting stored seeds against weevil infestation. |
