Fenilpropanoides de origen natural con actividad antialimentaria y repelente para el control de Tribolium Castaneum

Abstract

In the production chain of cereals, storage is one of the stages that requires more care, because it is in this where the greatest losses usually occur due to the attack of pests and diseases. One of the common pests in cereals and grinding products is Tribolium castaneum, popularly known as red flour weevil, an insect that generates a considerable detriment in productivity and high economic losses. Faced with this problem, the most effective and economic alternative found by farmers are synthetic agrochemicals, but their indiscriminate and permanent use has negatively affected human health and the environment, as well as generating resistance mechanisms in insects. The present work intends to contribute to the search of phytosanitary agents with potential application in the control of T. castaneum, through the study of the antifeedant and repellent action of some essential oils (AEs) and synthetic derivatives. The methodology included in the first stage, the extraction and chemical characterization of the essential oils of Piper asperiusculum, P. auritum and Artemisia dracunculus. Following the isolation of the major components present in the Aes and synthesis of the derivatives from the isolated and identified phenylpropanoids, which included reactions of oxidation with DDQ and reduction with H2 in Pd / C. Finally, the antifeedant and repellent activity against T. castaneum of the isolated and synthesized compound AEs was evaluated to establish some approximations of structure activity relationship. The chemical characterization of the essential oils indicated that the phenylpropanoids myristicin (38.1%) and dilapiol (35.3%), are the most abundant compounds in the essential oil of P. asperiusculum, safrole (62.1%) in that of P. auritum and estragole (88.5%) in the oil of A. dracunculus. From the isolated and identified natural compounds, six phenylpropanoids were synthesized with yields between 60 and 98%, corresponding to the aldehydes S-1 to S-3 obtained by oxidation with DDQ of the propenyl chain and the phenylpropans S-4 to S -6 obtained by catalytic hydrogenation with hydrogen and Pd / C of the side chain. The results of the repellent activity test indicate that the three AEs, the phenylpropane dilapiol and the S-1 S-3 S-4 and S6 derivatives exhibited a high repellent power 14 over T. castaneum. In the evaluation of the antifeedant activity, the AEs, isolated and synthesized phenylpropanoids, did not cause fagodisuasive effects on the insect pest. Finally, the study of the antifeedant activity carried out in this work corresponds to the first report of phage-disruptive effects for the three AEs, the fenilpropanoids estragol, dilapiol, myristicin and the derivatives S1 to S6. First, the repellent activity of dilapiol and synthetic derivatives (S-1 to S-6) on T.castaneum is reported for the first time.