Desenvolvimento de um método de análise de catequina e quercetina em extratos de espécies vegetais e fitoterápicos

Abstract

The secondary metabolites of plant species not only play an important role in the adaptation of plants to their ecosystems, but mainly represent a source of pharmacologically active substances. Among these metabolites are the flavonoids and condensed tannins (proanthocyanidins), because they have antioxidant and biological characteristics (such as antiinflammatory, antidiabetic). maria In order to benefit from the activities demonstrated by this class of compounds, several herbal extracts of plants have been developed. But it is known that a major challenge of this class of drugs is the monitoring of the active principle, in order to establish a normalization of the quality of the herbal medicine. The structural similarity between the classes of flavonoids makes the distinction between them very difficult if techniques such as mass spectrometry and nuclear magnetic resonance are not used but are not easily accessible because of their high cost. In this context, the development of faster and cheaper analytical techniques that are possible to be used in the proper monitoring of metabolites of phytotherapeutic interest is interesting. In this project, therefore, an electroanalytical technique was used to analyze the presence and content of flavanol and proanthocyanidins in commercial plant extracts and phytotherapics through metallic complexes. It was verified that the potentials of the non-complexed flavonoids, because they have near oxidation potentials, it is not possible to differentiate them by this technique. However, when complexed, it is observed that the 1064.3 mV potential of the catechin differs from the other complexes. This result is very promising because it was possible to differentiate the catechin from the other flavonoids through the complexation strategy using the differential pulse voltammetry technique.