[Larvicidal activity of tannins isolated of Magonia pubescens St. Hil. (Sapindaceae) against Aedes aegypti (Diptera, Culicidae)].

Phytochemical study of the larvicidal fractions which were carried out for the first time, isolated of the Magonia pubescens, monitored by the study of efficacy against the 3rd larval instar of Aedes aegypti, in the search of alternatives for the control of that mosquito and to obtain structures susceptible to chemical improving of the activity for the synthetic via of other derived. The fractions with biological activity were monitored chemically through chromatography of thin layer, using as revealing a solution acid of vanillin, analyzed by nuclear magnetic resonance of hydrogen and spectrometry of masses. The bioassays with the fractions were accomplished with five replications, controlled at the temperature of 28+/-1 degrees C, 80+/-5% of relative humidity and 12 h light. The found lethal concentrations of the fraction that it presented the largest potential larvicidal, MP-9, LC50 and LC90, were of 3.1 and 36.6 ppm, respectively. All the experiments were accompanied by a control series, containing the same number of larvae.