Quantificação de metabólitos secundários e avaliação da atividade antimicrobiana e antioxidante de algumas plantas selecionadas do Cerrado de Mato Grosso

Abstract

Ethanol extracts of Luehea paniculata, Anadenanthera colubrina, Cariniana rubra, Hancornia speciosa, Qualea grandiflora, Kielmeyera coriaceae and Palicourea rigida, collected in the Cerrado of Mato Grosso went through preliminary phytochemical analysis in order to identify major classes of secondary metabolites and also to quantify the total content of phenolics, flavonoids and coumarins. The study also describes the antimicrobial and antioxidant activity and the toxicity of the larva of Artemia salina. The C. rubra extracts and the Q. grandiflora were the most active against fungal strains of C. neoformans (MIC 3.91 μg/ml), C. krusei (MIC 15.63 μg/ml), C. parapsilosis (31.25 MIC μg/ml) and C. albicans (MIC 62.5 μg/ml), both with the same results for these organisms. Regarding the bacterial strains, the most sensitive one was the S. aureus with 250 μg/ml MIC for all the tested extracts. The Luhea paniculata and the Q. grandiflora were the most active against E. coli species (MIC 500 and 250 μg/ml, respectively) and E. faecalis (MIC 250 and 500 μg/ml, respectively). In the test of DPPH, K. coriaceae (Ca) (IC50 = 0.72 ± 0.51 μg/mL), K. coriaceae (Fo) (IC50 = 1.34 ± 0.53 μg/mL), H. speciosa (Fo) (IC50 = 1.03 ± 0.52 μg/mL), Q. grandiflora (Fo) (IC50 = 1.31 ± 0.19 μg/ml) and P. rigida (Fo) (1.39 ± 0,53 μg/ml) stood out. With the exception of the L. paniculata (Fo), which showed an IC50 of 14.40 ± 0.34 μg/ml and a flavonoid content of 295.5 mg/g, all species that had significant activity in the DPPH test, also showed flavonoid content similar to the standard one, or H. speciosa (Fo) (280.5 mg/g) Q. grandiflora (Fo) (260.5 mg/g), K. coriaceae (Ca) (250.5 mg/g), K. coriaceae (Fo) (235.5 mg/g).