Estudo voltamétrico do complexo de cobre(II) com o ligante vermelho de alizarina S, adsorvido na superfície do eletrodo de grafite pirolítico Voltammetric study of complex of copper (II) with alizarin red S ligand, absorbed on surface of pyrolytic graphite electrode

<abstract language="eng">The alizarin red S (ARS) has been used as a spectrophotometric reagent of several metals for a long time. Now this alizarin has been used as modifier agent of electrodes, for voltammetric analyses. In this work cyclic voltammetry experiments was accomplished on closed circuit, with the objective of studying the voltammetric behavior of alizarin red S adsorbed and of its copper complex, on the surface of the pyrolytic graphite electrode. These studies showed that ARS strongly adsorbs on the surface of this electrode. This adsorption was used to immobilize ions copper(II) from the solution

Atividade biológica de extratos, hidrolatos e óleos voláteis de pau-rosa (Aniba duckei Kostermans) e quantificaç ão do linalol no hidrolato de folhas

The objective of this study was to evaluate the bioactivity of extracts and by-products of volatile oil extraction from rosewood, as well as to quantify linalool levels in hydrolates. Branch and trunkwood methanol extracts presented significant lethality to Artemia franciscana larvae (LC 50 58 ± 33 and 71 ± 31 mg mL -1, respectively). Hydrolates (diluted to 25%) and volatile oil (2 mg mL -1) caused 100% mortality. These results show that A. duckei is a potential source of cytotoxic substances. The volatile oil obtained from branchwood presented larvicidal activity in vitro towards Aedes aegypti (hemorrhagic dengue fever vector, LC 50 2,2 g L -1). Quantitative GC analysis performed on the hydrolate obtained from leaf extraction revealed a linalool concentration of 0.09% v/v (6 mM), which could be responsible for the observed bioactivity