Phytochemical Analysis and Antioxidant Activity of Ethanolic Extracts from Different Parts of Dipteryx punctata (S. F. Blake) Amshoff

Abstract

The genus Dipteryx, to which the cumaru tree belongs, contains neotropical species native to Central and South American countries. They are used both in the sale of timber and seeds and for the extraction of the active compound coumarin, used as a flavoring agent. This study evaluated the phytochemical profile and antioxidant activity of extracts of leaves, branches, and fruits (residues and seeds) of the species Dipteryx punctata. The plant material for analysis was collected in five seed-producing areas, in Mojuí dos Campos, Pará, Brazil. The extracts were obtained via Soxhlet extractor using 92.8% distilled ethanol as the solvent and operated till exhaustion (8 h). Chromatographic analyses were performed by thin-layer chromatography (TLC) and gas chromatography coupled to mass spectrometry (GC-MS), followed by phytochemical determination of phenolics and flavonoids and analysis of antioxidant activity (TLC and free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH). The highest extract yields were obtained from D. punctata fruit residues and seeds from all areas, with maximum values of 26.1% and 47.2%, respectively, in Boa Fé (area 3). In the evaluation by TLC, the extracts of leaves, branches, and residues presented the classes of terpenes, condensed and hydrolysable tannins, and flavonoids; coumarin (1,2-benzopyrone) was identified only in residue and seed extracts. The major constituents highlighted in the collection areas were: lupeol in leaves (34.4% in area 5), 4-O-methylmannose in branches and residues (85.5% in area 2 and 90.6% in area 5, respectively), and coumarin in seeds (99.3% in area 3). The best results for the antioxidant action were obtained for extracts from leaves and residues, requiring a concentration of 117.6 µg.mL−1 of the extract from the leaves and 160.4 µg.mL−1 of the extract from the residues to reduce the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical by 50%. This phytochemical study contributes to reducing the scarcity of information on D. punctata. The chemical classes and compounds identified corroborate the antioxidant activity and add value to the species, and the data obtained reinforce the importance of reusing fruit residues, which are chemically rich but discarded in the environment.