Abstract Choisya ternata Kunth, C. ternata var. sundance Kunth and the hybrid Choisya ‘Aztec-Pearl’ are three related species belonging to the Rutaceae family. Ethanol extracts were prepared from the leaves of these three species and evaluated in relation to their antioxidant activity using in vitro and ex vivo models. The ethanol extracts belonging to the three species produced a very high antioxidant profile as evidenced by the DPPH radical scavenging activity, the determination of total phenolics and flavonoid equivalent. The generation of reactive species of oxygen in leukocytes stimulated with LPS was dramatically reduced when the three ethanol extracts were used. The alkaloids anhydroevoxine and choisyine were isolated from the ethanol extract of C. ternata using HEMWat (4:6:5:5) as the solvent system by means of high-speed countercurrent chromatography. This was the first time quinoline alkaloids were isolated from this species using HSCCC. These compounds were also assayed for their capacity to inhibit the generation of ROS in leukocytes stimulated by LPS and the results also suggested that they are reactive oxygenase inhibitors.

RESUMO Zeólitas naturais são materiais adsorventes eficientes e com baixo custo para remoção de metais pesados em relação aos métodos convencionais. Este trabalho teve como objetivo avaliar o efeito do pH na capacidade máxima de remoção de cobre (Cu+2) por zeólita natural disponível na região do planalto catarinense (zeólita basalto - ZB) comparando sua eficiência com uma zeólita comercial importada de cuba (ZC). A capacidade de troca de cátions das zeólitas foi determinada pelo método de saturação por amônio. A densidade de partículas foi feita através do método do balão volumétrico. O efeito do pH na remoção foi avaliado a pH 3,0; 4,0 e 5,0 (±0,2) e concentrações iniciais de 10 mg L−1 e 180 mg L−1. A capacidade máxima de remoção de Cu+2 foi avaliada em pH 3,0; 4,0 e 5,0 e concentrações iniciais de 10, 30, 60, 90, 180 e 270 mg L−1. A quantificação do teor de Cu+2 foi realizada por espectrofotometria de absorção atômica com sistema de atomização por chama do tipo ar-acetileno. Para a construção das isotermas foi utilizado regressão polinomial e no teste de médias da porcentagem removida de Cu+2 em diferentes valores de pH foi utilizado Scott-Knott a 5% de significância. A ZC apresentou capacidade de troca de cátions 40% superior a ZB, porém isso não se refletiu na capacidade de remoção. Houve efeito do pH somente para ZC na menor concentração adicionada. A capacidade máxima de remoção foi de 2662 mg kg−1 para ZB e 2759 mg kg−1 para ZC em pH 5,0. A capacidade máxima de remoção de Cu+2 para ZB é semelhante ao da ZC. A ZB pode ser utilizada na remoção de metais em efluentes industriais e laboratoriais com baixo custo.

ABSTRACT Natural zeolites are effective adsorbent materials and low cost for removal of heavy metals compared to conventional methods. This study aimed to evaluate the effect of pH and the maximum capacity removal of copper (Cu+2) by natural zeolite available in the region of Southern Brazil (zeolite basalt - ZB) comparing its perfomance with a commercial zeolite imported from Cuba (ZC). The cation exchange capacity of the zeolites was determined by Ammonium saturation method. The particle density was taken by volumetric flask method. The effect of pH on removal was measured at pH 3.0, 4.0 and 5.0 (± 0.2) and initial concentrations of 10 and 180 mg L−1. The maximum capacity removal of Cu+2 was assessed at pH 3.0, 4,0 and 5.0 and the initial concentrations of 10, 30, 60, 90, 180 and 270 mg L−1. Quantification of Cu+2 was carried out by atomic absorption spectrometry with atomization system type air-acetylene. For the construction of the isotherms was used polynomial regression and the averaged test percentage of Cu+2 removed at different pH values was used the Scott-Knott 5% significance level. The ZC presented capacity cation exchange 40% higher than ZB, but this was not reflected in the removal capacity. There was effect of pH only for ZC in less concentration added. The maximum removal capacity was 2662 kg−1 mg for ZB and 2759 mg kg for ZC in the pH 5.0. The maximum capacity removal Cu+2 ZB is similar to ZC. The ZB can be used to remove metals in laboratory and industrial effluents with low cost.