Estudo químico biomonitorado por ensaio com larvas Aedes aegypti das espécies Ocotea velloziana (Meisn.) Mez. e Aiouea trinervis (Meisn.)

Abstract

The chemical bioassay-guided study of components of plants has been adopted as a tool for obtaining active ingredients. The use of natural products for pest control and treatment of diseases is not new, it has been used before the advent of synthetic products. The biodiversity of the Cerrado and Pantanal is not well known and many species are endemic to these biomes. This chemical biomonitored study reports the results of biological test to verify the activity larvicide against mosquito larvae of Aedes aegypti (Linneus 1762) the ethanol extracts the stem bark of Ocotea velloziana (Meisn.) Mez. and fruits Aiouea trinervis (Meisn.). Phytochemical study consisted of the isolation, identification and elucidation structures of secondary metabolites responsible for the bio-activity presented the extracts. The ethanol extracts of the two species selected through the biologica larvicide test were subjected to chromatographic separation techniques including column chromatography on silica gel, silica gel 60 RP-18 of Sephadex LH-20 and high performance liquid chromatography reverse-phase efficiency. Structural determinations were made on the basis of spectroscopic data ¹H NMR, ³C and DEPT 135°, including bidimensional HSQC, HMBC, from information obtained from mass spectra and infrared and through the values specific optical rotation. Phytochemical bioactivity of extracts selected led to the isolation of three substances responsible for the activity larvicide: an alkaloid aporphine (S-dicentrine) of stem bark of Ocotea velloziana and two γ-lactone (isoobtusilactone A and obtusilactone A) of the fruits of Aiouea trinervis.