Abstract This study describes the synthesis and antioxidant activity of new 1,4-disubstituted 1,2,3-triazoles. These compounds were generated semi-synthetically using the Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC) reaction between ethyl 2-azidoacetate and terminal acetylenes derived from the natural products carvacrol, eugenol, isovanillin, thymol and vanillin. The products were obtained at 50 to 80% yield and characterised through several spectrographic techniques. Antioxidant activity was assayed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The products exhibited moderate antioxidant activity, with ethyl 2-(4-((4-formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl) acetate showing the highest antioxidant capacity (EC50 = 75.5 µg/mL) among the generated 1,4-disubstituted 1,2,3-triazoles. In conclusion, the generation of these compounds opens new possibilities for the development of new antioxidant agents.

A toxicidade de formulações comerciais de nim a Tetranychus urticae Koch (Acari: Tetranychidae) e a dois ácaros predadores, Euseius alatus De Leon e Phytoseiulus macropilis (Banks) foi estudada. A toxicidade tópica foi avaliada com três formulações comerciais (Natuneem, Neemseto e Callneem) e com o extrato de sementes de nim, todos na concentração de 1%, em comparação ao acaricida padrão, abamectina na concentração de 0,3ml/L e ao tratamento controle com água destilada. Com base no melhor efeito tópico sobre T. urticae, a formulação Neemseto foi selecionada para avaliar diferentes concentrações sobre ovos, e o efeito residual e repelente sobre adultos desses ácaros. O tratamento dos ovos consistiu na imersão em diluições de Neemseto por cinco segundos; e o efeito residual e repelente sobre adultos foi avaliado pela imersão de discos de folha nas diluições também por cinco segundos. A toxicidade de Neemseto a ovos e adultos foi maior para T. urticae comparada à toxicidade observada para os ácaros predadores. Neemseto foi repelente para T. urticae e E. alatus, quando testados nas concentrações 0,25; 0,50 e 1,00%, mas não afetou P. macropilis. A fecundidade de T. urticae foi reduzida significativamente por Neemseto em todas as concentrações, enquanto para os ácaros predadores, redução significante na fecundidade foi observada apenas nas maiores concentrações. Assim, nas formulações testadas, Neemseto foi o mais eficiente para o ácaro-rajado e provocou, relativamente, menor impacto aos ácaros predadores estudados.

The toxicity of selected commercial formulations of neem on Tetranychus urticae Koch (Acari: Tetranychidae) and two predatory mites Euseius alatus De Leon and Phytoseiulus macropilis (Banks) was studied. Topical toxicity was tested with the commercial formulations (Natuneem, Neemseto and Callneem) and extract of neem's seeds at concentration 1%, compared to the standard acaricide abamectin at concentration of 0.3 ml/L and the control treatment (distilled water). Based on the best performance against T. urticae through topical contact, the formulation Neemseto was selected to be evaluated using different concentrations against eggs, and residual and repellent effects on adults of the mites. Egg treatment consisted of dipping eggs into Neemseto dilutions and control treatment for five seconds. In addition, residual and repellent effects of Neemseto for adult mites consisted of using leaf discs dipped into the dilutions for five seconds. The toxicity of Neemseto on eggs and adults was greater for T. urticae compared to the toxicity observed for the predatory mites. Neemseto was repellent for T. urticae and E. alatus when tested at the concentrations of 0.25, 0.50 and 1.0%, and did not affect P. macropilis. Neemseto using all concentrations, while for the predatory mites significant reduction of mite fecundity was only observed at the largest concentrations reduced the fecundity of T. urticae significantly. So Neemseto, among tested neem formulations, performed better against the twospotted spider mite and exhibited relatively low impact against the predatory mites studied.