Síntese de derivados da amida natural piperina e avaliação da atividade inseticida contra larvas de Aedes aegypti

Abstract

This work is part of a research project which investigates the use of abundant and accessible natural products in the synthesis of new molecules with potential biological activity. Piperine is an amide extracted with high yelds from the dry fruits of Piper nigrum. Recent studies, carried out in our laboratory, showed antiparasitic activity against Trypanossoma cruzi for piperine and for a series of its derivatives and analogues. Insecticidal activity against muscoid dipteran species was also observed, which had already been described in the literature for other piperine analogues. We describe the synthesis of a series of amide derivatives of piperine replacing the piperidine ring with other cyclic amides. We also describe another series developed by reduction of the double bonds of piperine together with reactions on the aromatic ring. All compounds were characterized by conventional methods of analysis (IR, NMR, GC-MS) and evaluated for their toxic effects against Aedes aegypti larvae through methodology recommended by the World Health Organization. The results obtained show that tetrahydropiperine possesses the best activity profile. The results are satisfactory considering other natural products with larvicidal activity reported in the literature.