Estudo fitoquímico e potencial antioxidante de Caryocar Villosum (Aubl.) Pers. (PIQUIÁ)

Abstract

Caryocar villosum is a tree found in the central Amazon, belonging to the Caryocaraceae family, popularly known as Piquiá. Previous phytochemical and pharmacological studies with some species of the genus Caryocar indicated substances with biological properties. Thus, the objective of this study was to characterize the chemical constituents present in the extracts of the stem bark (obtained by chemometric analysis) of C. villosum through the technique of mass spectrometry, nuclear magnetic resonance and evaluation of the antioxidant potential in vitro. Based on the chemometric analysis, using the Snyder triangle method, in which methods based on projection (PCA - Principal Component Analysis) and methods based on the distance between (HCA - Hierarchical Cluster Analysis), also known as Cluster, were selected only as the first group of extracts that make up triangle 1 (acetone, methanol and water) for the characterization based on the fragmentation pattern of the substances compared with the data in the literature. Cascades were used to characterize 7 phenolic substances, namely: gallic acid, ellagic acid, ramnoside ellagic acid, dilactone vanoleic acid, 3,6 - di - O - gallo - D - glucose, 3,4,6 - tri‐ O - Galloil - D - Glucose and 1,2,3,6 - Tetra - O - Galloil - β - D - Glucose. The extract based on methanol was highlighted as the most representative to contain the phenolic compounds. With this, it was possible to confirm the identification through isolation 03 substances: ellagic acid, ellagic acid ramnoside and 3,6 - di - O - gallo - D - glucose in which two of them were identified as being the associated substances by the separation of the groups chemometrics. The evaluation of the content of phenolic compounds, carried out by the Folin-Ciocalteu method, showed that a type C. villosum presented a percentage of phenolics in its extracts between 20.2 to 36.9%, with a higher content for the extract AcOEt / H2O / EtOH, with 329.4 μg EAG / g. All extracts obtained a high total percentage of DPPH free radical inhibition between 91.3 to 95.3% (with EC50 in the inhibition range between 3.5 to 6.7 μg.mL), 1 with the exception of aqueous extract that obtained an inhibitory percentage of 46.0%. The isolated substances also showed a high percentage of DPPH inhibition with EC50 at concentrations of 5.6 μg.mL for P1 (3,6-di-O-galloyl-D-glucose) 12,3 μg.mL for P2 (ramnoside ellagic acid) and 5.6 μg.mL for P3 (ellagic acid). Thus, the part used of the species C. villosum proved to be a promising source of phenolic compounds with antioxidant activity in vitro.