Oleandrin concentrations in leaves of Nerium oleander of different colors of flowering/Concentracoes de oleandrina nas folhas de Nerium oleander de diferentes cores da floracao

Nerium oleander is an ornamental plant responsible for poisoning in animals and humans. All parts of the plant contain cardiotoxic glycosides, mainly oleandrin. Some authors suggest that the toxicity of the plant would present a dependence on flower color. The objective of this study was to determine whether there is variation in the concentration of oleandrin in the leaves of N. oleander specimens of different colors of flowers. Ten samples of leaves from each variety of flower (white, pink and red) were collected. Oleandrin levels were determined by HPLC-UV after extraction with methanol, precipitation with lead acetate and separation with C18 cartridge. The average concentration obtained in all analyzed leaves was 4.89mg [g.sup.-1], being 6.20 [+ or -] 4.08mg [g.sup.-1] in variety of white flowers, 4.16 [+ or -] 3.44mg [g.sup.-1] in pink flowers, and 4.31 [+ or -] 1.99mg [g.sup.-1] in red flowers. The concentrations of oleandrin did not show statistically significant difference between the varieties of flowers.