Desenvolvimento e validação de metodologia analítica para análise da fração acetato de etila do extrato da casca do caule de Anacardium occidentale Linn por cromatografia líquida de alta eficiência

Abstract

Anacardium occidentale Linn is a tree native to Brazil, popularly known as cashew. Studies show that the Ethyl Acetate fraction (EtOAc) obtained from the acetone:water extract of the A. occidentale stem bark has anti-inflammatory activity, suggesting tannins as responsible for this action. As one of 71 species of the National List of Medicinal Plants of Interest to the Unified Health System (RENISUS), it is important that analytical methodologies for the study of its constituents are developed. In this context, the High Performance Liquid Chromatography (HPLC) is a method of importance to the analysis of samples of plant origin. This study aimed to develop and validate an analytical methodology by HPLC for analysis of EtOAc fraction of acetone:water extract from the stem bark of A. occidentale. The chromatographic conditions were established using acetic acid 0.3% (v/v in water) and acetonitrile as the mobile phase. As a starting point for the development of chromatographic procedures, exploratory gradient was used, which allows to analyze all polarity groups. The gradient elution was then adjusted to obtain a chromatogram with adequate separation and satisfactory chromatographic parameters. For identification of the compounds, the pattern analysis was carried out, and by observing the retention times and absorption spectra of the substances was possible to choose those which would be present in the sample. It could suggest the presence of catechin, epicatechin, epigallocatechin and gallic acid in the EtOAc fraction of A. occidentale. To validate the method, linearity tests were performed, precision, accuracy, robustness, limits of detection and quantification. According to Resolution 899/2003 (ANVISA), the method was assessed to be linear, precise and accurate for the studied compounds. Among the changed analysis conditions for studying the robustness of the method, when the column temperature was 35°C analysis did not present robustness for gallic acid, but when other conditions were changed it did not promote statistically significant changes to this analyte. It follows that the chromatographic method is suitable for analysis of gallic acid, catechin and epicatechin in EtOAc fraction of the acetone:water extract of the A. occidentale.