Determination of polyphenols in Schinus terebinthifolius Raddi bark extracts and chemometric analysis

This work describes a comparison of HPLC and spectrophotometric methods to determine the variation of the polyphenolics catechin, gallic acid, epicatechin, rutin, quercetin and chlorogenic acid in extracts of barks of Schinus terebinthifolius Raddi (Anacardiaceae). This plant is a well-known medicinal plant that occurs in South and Central America and it is employed in folk medicine mainly as antimicrobial, anti-inflammatory and antipyretic and, it is also commercialized as herbal medicines. Samples of S. terebinthifolius were collected in different habitats of the Brazilian semi-arid region and commercial samples were bought in local drugstores. The samples were submitted to ethanol:H2O extraction and the extracts were submitted to HPLC-DAD to the best separation of compounds. Besides, a validation method for quantification of the above chemical markers was obtained and the concentration of compounds was determined in all samples, including the reference sample and commercial herbal medicines. In the same way, a methodology based on simple UV-VIS spectrophotometric analyses was also developed and the concentration data of the chemical markers were obtained for all samples. Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) and the six active compounds were determined and analyzed. The chromatograms showed similar chemical profiles but some differences in intensities were observed. HCA and PCA permitted to group the samples with similar chemical composition and paired multivariate analyses of the obtained sample compositions from HPLC/DAD and UV-VIS analyses showed both methods are similar and, they permitted to indicate the main chemical markers responsible for the quality of the herbal medicines.