Antioxidant and antimicrobial properties of ethanolic extract of Libidibia ferrea pods / Propriedade antioxidante e antimicrobiana do extrato etanólico de vagens de Libidibia ferrea

Libidibia ferrea is a typical plant of northern and north-east Brazil and has well-known medicinal properties that can be found in ethanolic extracts such as antipyretic, anti-inflammatory and anti-rheumatic compounds. This study seeks to evaluate the potential antioxidant and antimicrobial activity of ethanol extracts from Libidibia ferrea pods. The pods were used for the preparation of ethanolic extracts of L. ferrea which is used to determine biological activity, and measure their total phenolic content. For quantification of antioxidant methods of DPPH, ABTS and ß-carotene were employed and the method of minimum inhibitory concentration (MIC) to measure the antimicrobial activity. The ethanolic extract of L. ferrea showed excellent antioxidant activity, as well as other similar substances commonly used for this purpose such as citric acid and trolox. In addition, it had antimicrobial activity against Gram-negative and Gram-positive bacteria.(AU)

Libidibia ferrea é uma planta típica do norte e nordeste do Brasil conhecida por suas propriedades medicinais que podem ser encontrados em extratos alcoólicos, possui compostos antipiréticos, anti-inflamatórios e antirreumáticos. Este estudo visa avaliar o potencial antioxidante e atividade antimicrobiana do extrato etanólico de vagens de Libidibia ferrea. As vagens foram empregadas na preparação de extrato etanólico de L. férrea, utilizado na determinação da atividade biológica, e para mensurar seu conteúdo fenólico total. Os métodos DPPH, ABTS e ß-caroteno foram utilizados para quantificar a atividade antioxidante, e o método da Concentração Inibitória Mínima (CIM) para avaliar a atividade antimicrobiana. O extrato etanólico de L. ferrea apresentou atividade antioxidante excelente, bem como outras substâncias compatíveis normalmente utilizadas para este fim, tais como ácido cítrico e trolox. Além disso, demonstrou atividade antimicrobiana contra bactérias Gram-negativas e Gram-positivas.(AU)

Quantification, antioxidant and antimicrobial activity of phenolics isolated from different extracts of Capsicum frutescens (Pimenta Malagueta).

This paper presents the quantification, antioxidant and antimicrobial activity of capsaicin, dihydrocapsaicin and the flavonoid chrysoeriol isolated from different extracts (hexane and acetonitrile extracts from whole fruit, peel and seed) of Capsicum frutescens (pimenta malagueta). The acetonitrile extract of the seeds, peel and whole fruits contained capsaicin as a major component, followed in abundance by dihydrocapsaicin and chrysoeriol. The antimicrobial activity of the isolated compounds against seven microorganisms showed chrysoeriol was the most active compound. In the antioxidant test, the acetonitrile extract from the whole fruit showed the highest activity. The antioxidant activity of pimenta malagueta may be correlated with its phenolic content, principally with the most active compound, capsaicin.

Antileishmanial Phenylpropanoids from the Leaves of Hyptis pectinata (L.) Poit.

Hyptis pectinata, popularly known in Brazil as "sambacaitá" or "canudinho," is an aromatic shrub largely grown in the northeast of Brazil. The leaves and bark are used in an infusion for the treatment of throat and skin inflammations, bacterial infections, pain, and cancer. Analogues of rosmarinic acid and flavonoids were obtained from the leaves of Hyptis pectinata and consisted of two new compounds, sambacaitaric acid (1) and 3-O-methyl-sambacaitaric acid (2), and nine known compounds, rosmarinic acid (3), 3-O-methyl-rosmarinic acid (4), ethyl caffeate (5), nepetoidin A (6), nepetoidin B (7), cirsiliol (8), circimaritin (9), 7-O-methylluteolin (10), and genkwanin (11). The structures of these compounds were determined by spectroscopic methods. Compounds 1-5, and 7 were evaluated in vitro against the promastigote form of L. braziliensis, and the ethanol extract. The hexane, ethyl acetate, and methanol-water fractions were also evaluated. The EtOH extract, the hexane extract, EtOAc, MeOH:H2O fractions; and compounds 1, 2 and 4 exhibited antileishmanial activity, and compound 1 was as potent as pentamidine. In contrast, compounds 3, 5, and 7 did not present activity against the promastigote form of L. braziliensis below 100 µM. To our knowledge, compounds 1 and 2 are being described for the first time.