Avaliação da atividade antimicrobiana e antiradicalar dos extratos e substâncias dos frutos de Buchenavia tomentosa –Eichler (Combretaceae) e Ouratea spectabilis Aubl. (Ochnaceae)

Abstract

This thesis presents the study of bioactivity evaluation of antiradical and antimicrobial activity of two plants: Buchenavia tomentosa (Combretaceae) and Ouratea spectabilis. Isolated compounds were identified using Nuclear Magnetic Resonance technique 1H, 13C, and two-dimensional. The study phytochemical study led to identification of 23 substances, seven Buchenavia tomentosa, phenolic acid, ethyl gallate (1), methyl gallate (2), Gallic acid (3); hydrolysable tannins: corilagina (4), buchenavina (5) and lignans pinoresinol (6) and epipinoresinol (7). Sixteen Ouratea spectabilis; biflavonoids: 8-chloro 7, 7' dimetilagastinoflavona (8), 6,6 ' bigenkwanina (9), 7,7' dimetilavolkensiflavona (10), 7,7' dimetoxiagastiflavona (11), 3,8' bipegenina (12) and 7,7' agastiflavona (22), the isomer of pinoresinol (13A), butanolideo: isochinosídeo A to D (14, 15, 19 and 20 respectively), seco-ochinosídeo (16), isolinderanolídeo E (17), ochinosídeo (18), the steroid β-sitosterol (21) and coumarin 7,7' hydroxy-bicumarina (23). The assay was performed using a microdilution technique, the ethanol extract, fractions, subfractions and isolated compounds were tested against bacterial activity with Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis. The antifungal testing with Candida albicans, Candida Krusei, Candida parapsilosis, Candida glabrata and Cryptococcus neoformans. To evaluate antiradical test was performed with the method free radical 2,2-diphenyl-1- picrylhydrazyl (DPPH). The most significant results activity antibacterial compounds were submitted by the O. spectabilis 7.7' dimetoxiagastiflavona (11), seco-ochinosídeo (16) and isolinderanolídeo (17) against E. faecalis with minimum inhibitory concentration in 25 μg/mL. In the test antifungal compounds B. tomentosa were more active, the corilagina (4) against C. parapsilosis (1,56 μg/mL) and buchenavina (5) for C. glabrata (3,125 μg/mL). As for the antiradical activity was most active corilagina 1,72 ± 0.09 uM. With this result we can conclude that the fruits of B. tomentosa, showed better antifungal and antioxidant activity and the fruits of O. spectabilis antibacterial activity.