Estudo químico e atividade Larvicida de (Sideroxylon obtusifolium Humb. ex Roem & Schult) T.D. Penn (Sapotaceae)

Abstract

This work describes the isolation of some chemical constituents and evaluation of larvicidal activity (larvae of the 4º instars of Aedes aegypti L.) from the extracts of stem bark of Sideroxylon obtusifolium (Roem. & Schult.) T.D. Penn (Sapotaceae). Among extracts tested in the larvicidal assays, only chloroform (100% of mortality at 24h) and hexane (60% and 66.67% at 24h and 48h, respectively) fractions showed, at concentration of 250 ppm, promising results. Chloroform fraction was tested at different concentrations (250, 200, 150, 100 and 50 μg/mL), which results enabled us to determine its LC50 (100.08 μg/mL) with their respective confidence intervals at 95% (88.74-110.93 μg/mL). The literature does not report any study involving larvicidal activity for the genus Sideroxylon. Phytochemical study with these fractions conduced to the isolation of a mixture of two phytosteroids (-sitosterol and stigmasterol), a pentacyclic triterpene (betulinic acid), an ester derivative of cinnamic acid (ethyl ester of 4-methoxycinnamic acid) and glycosylated phytosteroid (3-O--D-glucopyranosyl-α-spinasterol). These substances had their structures identified based on analysis of NMR data and by comparison with literature data and although they are all known and frequently occur in higher plants, they are described for the first time in this species.