Activity of Ricinus communis (Euphorbiaceae) and ricinine against the leaf-cutting ant Atta sexdens rubropilosa (Hymenoptera : Formicidae) and the symbiotic fungus Leucoagaricus gongylophorus

The focus of this study was the identification of compounds from plant extracts for use in crop protection. This paper reports on the toxic activity of fractions of leaf extracts of Ricinus communis L (Euphorbiaceae) and isolated active compounds in the leaf-cutting ant Atta sexdens rubropilosa Forel and its symbiotic fungus Leucoagaricus gongylophorus (Singer) Moller. The main compounds responsible for activity against the fungus and ant in leaf extracts of R communis were found to be fatty acids for the former and ricinine for the ants. (C) 2004 Society of Chemical Industry.

Activity of Ricinus communis (Euphorbiaceae) and ricinine against the leaf-cutting ant Atta sexdens rubropilosa (Hymenoptera : Formicidae) and the symbiotic fungus Leucoagaricus gongylophorus

The focus of this study was the identification of compounds from plant extracts for use in crop protection. This paper reports on the toxic activity of fractions of leaf extracts of Ricinus communis L (Euphorbiaceae) and isolated active compounds in the leaf-cutting ant Atta sexdens rubropilosa Forel and its symbiotic fungus Leucoagaricus gongylophorus (Singer) Moller. The main compounds responsible for activity against the fungus and ant in leaf extracts of R communis were found to be fatty acids for the former and ricinine for the ants. (C) 2004 Society of Chemical Industry.

Isolamento do alcalóide ricinina das folhas de Ricinus communis (Euphorbiaceae) através de cromatografias em contracorrente

Droplet counter-current chromatography, rotation locular counter-current chromatography and high-speed counter-current chromatography were applied to the preparative separation of the alkaloid ricinine from the dichloromethane extracts of Ricinus communis leaves. The solvent system used was composed of dichloromethane-methanol-water (93:35:72 v/v/v) and all techniques led to the isolation of large amounts of the alkaloid. The best result was obtained through HSCCC, since the ricinine yield was respectively 50% and 30% higher than when using RLCCC or DCCC.

Suscetibilidade de operárias e larvas de abelhas sociais em relação à ricinina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of castor cake and elephant grass composting on edaphic fauna

Elephant grass and castor cake when combined can make a promising organic fertilizer. However, castor cake contains potentially toxic chemicals, such as ricin and ricinine. To test potential effects of these chemicals, compost piles of elephant grass ( Pennisetum purpureum Schum.) with castor cake were prepared with different C:N ratios (T1 = 40, T2 = 30, T3 = 20; T4 = 30 [control, elephant grass + crotalaria]) to evaluate colonization by edaphic fauna and any suppressive effects of castor cake. Soil organisms were collected with Berlese-Tullgren funnels. There were temporal differences between the treatments, and the epigeous fauna was mainly represented by members of the Acari and Entomobryomorpha. Elapsed time is the major factor in determining the composition of the epigeous fauna community associated with composting, indicating that castor cake has no suppressive effect.