Análise do potencial fitoquímico de Ximenia americana e capacidade antiglicante da mangiferina e dos extratos metanólicos obtidos das folhas de café.

Abstract

The present work presents the evaluation of some pharmacological properties and chemical composition of Ximenia americana (X. americana) leaf, stem and root extracts, as well as the evaluation of the antiglycant capacity of methanolic extracts of coffee leaves and one of its constituents, the mangiferin. With respect to the pharmacological properties of X. americana, a promising antioxidant action of the root and stem methanolic extracts was verified in relation to the radicals DPPH and ABTS. The acetylcholinesterase enzyme inhibition assay, which is related to a possible pharmacological action in the treatment of Alzheimer's disease, revealed a significant potential for the methanolic extracts of the leaves, considering that it had a halo size equal to the eserine pattern. Data on the chemical constitution of methanolic extracts from all evaluated parts of this plant demonstrated a very diverse composition of polyphenolic compounds (flavonoids, phenolic acids and the like), being the first time that most of these substances were identified in this species and are being reported in the literature. A total of 19 compounds have been identified: gallic acid, gallic acid quinate, 3,4-dihydroxybenzoic acid, procyanidin B1, (+) - catechin, chlorogenic acid, procyanidin B2, (-) - epicatechin, procyanidin C1, tetrameric procyanidin, pentameric procyanidin, 3 position isomer compounds of quercetin arabinoside, quercetin rhamnoside, 3 position isomer compounds of kaempferol arabinoside, and kaempferol rhamnoside. From the quantitative analysis of the leaves, stem and root methanolic extracts performed by high performance liquid chromatography, quercetin rhamnoside was obtained as the major compound in the leaves, with a content of 17,998 g / kg of dry leaves. In the stem and root extracts, the major compounds were (+) - catechin, with 12,581 g / kg and (-) - epicatechin, with 8.547 g / kg dry mass, respectively. The evaluation of the antiglican capacity of the methanolic extracts of coffee presented a satisfactory result only for one of the samples of evaluated coffee species. The mangiferin, present in the extracts of the evaluated coffee leaves, has been shown to be a substance with a high anti-glycation, that is, capable of preventing the formation of Advanced Glycation Products (AGEs). This ability is justified by the formation of adducts from the reaction between mangiferin and reactive carbonyl species (RCS), such as glyoxal (GO) and methylglyoxal (MG). The mechanisms of adduction were proposed.