Caracterização quimica e biológicas de Diplotropis purpurea (Rich.) Amshoff (Fabaceae)

Abstract

Diplotropis purpurea (Fabaceae), is much used for the resistance of its wood. The present study performed the phytochemical study of the leaves and branches of D. purpurea and evaluated the activities of toxicity, antibacterial and antiangiogenic. The collection of the samples was performed at the "cachoeira da onça", Presidente Figueiredo, AM. The material was dried, ground and extracted with methanol (MeOH). The phytochemical study of the leaves provided the steroids stigmasterol and -sitosterol, the triterpene lupeol and the flavonoids catechin, quercetin, isoorientin and the proanthocyanidin B1, kaempferol and catechin. From the branches were isolated the steroids stigmasterol and  -sitosterol, the triterpene lupeol and the flavone 7,4’-dimethoxy-3-hydroxyflavone, apigenin, 3,5,6,4’-tetrahydroxystilbene and the procyanidin C1, kaempferol and catechin. Regarding the toxicity activity against the microcrustacean Artemia salina, the methanolic and aqueous extracts presented mortality rate above 50% in the concentration of 1000 μg/mL, considered a great result, however, they did not present the same result when diluted in lower concentrations, presenting results below the expected. Regarding the antimicrobial activity by the agar diffusion method, the MeOH extract and the DCM phases of leaves and branches presented high activity against the bacteria Bacillus cereus and Pseudomonas fluorescens, with inhibition zones of 11 to 19 mm and 9 to 17 mm respectively. In the microdilution assay the branch MeOH sample in the concentration of 1000 μg/mL was active against M. morganii, and the branch AcOEt phase sample in the concentration of 1000 μg/mL against A. baumanii and 500 μg/mL were active against M. morganii. The extracts and phases of leaves and branches presented from medium to high antiangiogenic activity, and of the three substances tested (stigmasterol, lupeol and quercetin) the stigmasterol 1000 μg/mL was highly toxic, leading the embryo to death. The present study stands out for contributing to the enrichment of scientific knowledge, since biological activities and substances not yet identified were reported both for the species D. purpurea as well as for its genus.