Preliminary evaluation of the in vitro biological activities of crude wood extracts of Dinizia excelsa Ducke obtained using methanolic, aqueous, acetonitrile, dichloromethane, chloroform, and hexane solvents.

This study reports an exploratory in vitro screening of the biological potential of Dinizia excelsa Ducke, an Amazonian species and the only representative of its genus. Six wood extracts were prepared using solvents of different polarities and compared regarding their phytochemical profiles and biological activities. The methanolic extract presented the highest yield, followed by aqueous and acetonitrile extracts, which also contained the largest amounts of phenolics, flavonoids, flavonols, hydrolyzable tannins, saponins, and alkaloids. In antioxidant assays, polar extracts showed IC₅₀ values of 25.3-45.3 µg/mL (DPPH), 15.1-30.0 µg/mL (ABTS), 105-135 µg/mL (NO• and OH•), and 110.0-180.0 µg/mL (FRAP, CUPRAC, phosphomolybdenum, ferricyanide). Cytotoxicity tests revealed moderate effects against tumor cells (27.6-45.6 µg/mL), low toxicity in normal mammalian cells, and absence of hemolysis. Antimicrobial activity occurred against Gram-positive and Gram-negative bacteria and Candida spp. (16-512 µg/mL). Antiparasitic assays showed IC₅₀ values of 32.4-73.0 µg/mL against Trypanosoma cruzi, Leishmania amazonensis, Schistosoma mansoni, and Plasmodium falciparum. These findings indicate that D. excelsa wood residues contain bioactive compounds with measurable antioxidant, antimicrobial, and antiparasitic properties. The results provide a preliminary foundation for future studies focused on isolation, structural elucidation, and mechanistic evaluation of active metabolites.