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Considering the economic potential of secondary metabolites, researches have been focusing several strategies in order to explore and enhance the accumulation of these metabolites in plant matrices in a broad context. One of those strategies is the development of suitable methodologies for the determination of some elicitors, such as salicylic acid (SA). Since literature presents only a few analytical methods for the quantification of SA in plants, this study developed, validated and evaluated these metabolite contents in Polygala species using capillary zone electrophoresis with ultraviolet-visible detection. The background electrolyte (BGE) consisted of 15 mmol L−1 of hydroxymethyl-aminomethane and 30 mmol L−1 of 2-hydroxy-isobutyric acid, pH = 3.9. The BGE was chosen using a rational procedure to increase selectivity and reduce migration time. The method presented rapid performance, migration time less than 0.76 min for salicylic and phthalic acid (internal standard), precision results for peak area were better than 2.9% (intra-day) and 2.8% (inter-day) and the responses for the analytes were linear (range of 1-5 mg L−1), with limits of detection and quantification of 0.2 and 0.6 mg L−1, respectively. The developed method was applied for 39 samples of plant extracts.

Since its inception in the 80's, capillary electrophoresis has matured into a well-established separation technique, actually encompassing a family of electrodriven techniques with distinct separation mechanisms and selectivity, performed in a single capillary column. In this work, the versatility of capillary electrophoresis in handling materials from a diversity of chemical classes and complex sample matrices is illustrated by representative applications in the clinical, forensic, cosmetological, environmental, nutritional and pharmaceutical areas, grouping together our own research interests and results. Desde sua implementação na década de 80, a eletroforese capilar vem evoluindo, tornando-se uma técnica de separação bem estabelecida e, hoje, engloba de fato, uma família de técnicas eletrocinéticas, com mecanismos de separação distintos e seletividade característica, todas passíveis de serem conduzidas em uma única coluna capilar. Neste trabalho, a versatilidade da eletroforese capilar para lidar com materiais de diferentes classes químicas e matrizes complexas é ilustrada, apresentando aplicações representativas nas áreas clínica, forense, cosmética, ambiental, nutricional e farmacêutica, compilando os interesses de pesquisa e resultados do nosso próprio grupo.

The determination of fatty acids (FA) in liver from three different groups of Wistar rats (six rats by group) submitted to diet (AIN-93G) by capillary zone electrophoresis (CZE) was proposed. Each group received the same diet. However, the soybean oil used to prepare the feed, whose amount was 7% w/w, had different origins. The first group was fed with feed containing soybean oil fresh; the second one was fed with soybean used during 7 days in deep frying process; finally, the third was fed with soybean used during 15 days in deep frying process. After 45 days the rats were submitted to euthanasia and the FA amount in liver was successful monitored by CZE in a simple, fast and efficient way. The results obtained were compared to gas chromatography official method and no significant differences were observed within 95% confidence interval. The electropherograms to FA analysis were submitted to principal component analysis (PCA) being possible to discriminate the final from the control and intermediate groups. In addition to PCA results, the low density lipoprotein (LDL) was evaluated indicating that the total time exposure of the oil submitted to deep frying processes can be considered relevant to evaluating the oil quality.

A phytochemical investigation of Polygala molluginifolia (root, stem, leaves and flowers) resulted in the isolation of four pyranoisoflavones, of which isoflavone 1 was previously unknown in the literature. Isoflavones 2-4: , although they are known synthetic compounds, are described in this work as new natural products. The isolated compounds were evaluated for their antioxidant effects and potential for inhibiting the acetylcholinesterase enzyme. Isoflavones 1 and 4 inhibited acetylcholinesterase, displaying IC50 values of 68 µmol L-1 and 84 µmol L-1, respectively. In the DPPH assay, the same compounds and rutin 5 exhibited EC50 values of 61 µmol L-1, 55 µmol L-1 and 16 µmol L-1, respectively. Moreover, the permeability of compounds 1-4: was evaluated using parallel artificial membrane permeability assay (PAMPA) with isoflavones 3 (9.25 × 10-6 cm s-1) and 4 (3.48 × 10-6 cm s-1) exhibiting the highest permeabilities.