Grain-protectant compounds from Duguetia lanceolata (Annonaceae) derivatives: Bioassay-guided searching and toxicity against the maize weevil. (January 2020)

• Record Type: Journal Article
• Authors: Domingues, Vanessa de Cássia; Ribeiro, Leandro do Prado; Gonçalves, Gabriel Luiz Padoan; Forim, Moacir Rossi; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Vendramim, José Djair
• Is Part Of: Journal of stored products research. Volume 85(2020)
• Publication Date: 2020-01
• Subjects: Allelochemicals -- Sitophilus zeamais -- Chromatographic techniques -- Steroids -- 2, 4, 5-Trimethoxystyrene; Food -- Storage -- Periodicals; Farm produce -- Storage -- Diseases and injuries -- Periodicals; Entomology -- Periodicals; Food Contamination -- Periodicals; Food Preservation -- Periodicals; Insect Control -- Periodicals; Aliments -- Entreposage -- Périodiques; Produits agricoles -- Entreposage -- Maladies et dommages -- Périodiques; Electronic journals; 631.568
• DOI: 10.1016/j.jspr.2019.101549
• Languages: English
• ISSNs: 0022-474X

Abstract

Abstract: In order to obtain bioactive allelochemicals from Neotropical Annonaceae, bioguided chromatographic fractionations with derivatives prepared from Duguetia lanceolata St.-Hil. leaves were performed using the maize weevil, Sitophilus zeamais Mots. (Coleoptera: Curculionidae), as bioindicator, which is a primary insect pest of stored cereals in tropical conditions. For this end, four phases (hexane, dichloromethane, ethyl acetate and hydroalcohol) were obtained firstly by liquid-liquid partition and tested through a residual contact bioassay (at 1500 mg L −1 ) in order to verify their bioactivity on adults of the maize weevil. Only the hexanic fraction caused significant mortality (74%) after the tenth day of insect exposure on treated samples of grains corn. Thus, thisfraction was separated into seven new subfractions by means of vacuum column chromatography and solvents of increasing polarities. Subfraction 2 promoted 90% of mortality whereas subfraction 6 promoted 30% of mortality of maize weevils. The aromatic compound 2, 4, 5-trimethoxystyrene and a mixture of steroids [campesterol (8.44%) + stigmasterol (12.37%) + sitosterol (79.19%)] were isolated from subfraction 2 and promoted promising grain protective activity, in a manner comparable to a diatomaceous-earth based formulation (our positive control). Furthermore, the results reported in the present study demonstrate the potential application of derivatives of D. lanceolata leaves in integrated pest management (IPM) of stored grains, mainly in the framework of maize weevil management. Highlights: Bioguided chromatographic fractionations with derivatives prepared from Duguetia lanceolata leaves were performed against Sitophilus zeamais . 2, 4, 5-trimethoxystyrene and a mixture of steroids were isolated from bioactive fraction. These compounds promoted promising grain protective activity against maize weevil. The level of bioactivity of isolated compounds was comparable to a diatomaceous-earth based formulation.