Characterization, antibacterial activity and antibiotic modifying action of the Caryocar coriaceum Wittm. pulp and almond fixed oil.

In this study the physicochemical characterization of the pulp and almond fixed oil was carried out; their antibacterial activity and aminoglycoside antibiotic modifying action against standard and multiresistant Gram-positive and -negative bacteria were investigated using the broth microdilution assay. Physical properties such as moisture, pH, acidity, peroxide index, relative density and refractive index indicate stability and chemical quality of the oils. In the GC/MS chemical composition analysis, a high unsaturated fatty acid content and the presence of oleic and palmitic acids were observed in the oils. In the antibacterial assay, more significant results were obtained for Escherichia coli, while other standard and multi-resistant strains presented MIC values ≥ 1024 µg/mL. Furthermore, the fixed oils in association with antibiotics were able to significantly improve antibacterial activity against S. aureus with a reduction in MICs.

HPLC and in vitro evaluation of antioxidant properties of fruit from Malpighia glabra (Malpighiaceae) at different stages of maturation.

Malpighia glabra L. is indicated for the treatment of diseases due presenting several medicinal properties. The aim of the present study was quantify phenolic compounds and carotenoids, additionally, evaluate the antioxidant potential of different methanolic fractions (mature stage, intermediate stage and green maturity stage) of Malpighia glabra. Methanolic fractions of the three stages of maturation were characterized using HPLC-DAD. The antioxidant activity of fractions was evaluated using in vitro assay systems: iron-chelating activity (Fe2+), inhibition of the radical 1-1-diphenyl-2-picrylhydrazyl (DPPH) and inhibition of production of thiobarbituric acid reactive substances (TBARS). In quantifying compounds by HPLC-DAD showed that the compounds rutin and quercetin showed the highest peaks in the three samples tested. Regarding carotenoids, the ß-carotene stood in the analyze. The methanolic fraction of lyophilized pulp of green fruits showed better results for iron chelation and DPPH tests; TBARS by the methanolic fraction of the ripe fruits showed lower IC50 as the basal. When in the presence of iron as an inducer of peroxidation, the methanolic fraction of the pulp of green fruits showed the lowest IC50. Our research indicates that the o fruits of M. glabra good potential in scavenging free radicals and can be an important source of antioxidant phytochemical.

Synthesis, antibacterial and cytotoxic activities of new biflorin-based hydrazones and oximes.

Biflorin 1 is a biologically active quinone, isolated from Capraria biflora. Five new biflorin-based nitrogen derivatives were synthesized, of which two were mixtures of (E)- and (Z)- isomers: (Z)-2a, (Z)-2b, (Z)-3a, (Z)- and (E)-3b, (Z)- and (E)-3c. The antibacterial activity was investigated using the microdilution method for determining the minimum inhibitory concentration (MIC) against six bacterial strains. Tests have shown that these derivatives have potential against all bacterial strains. The cytotoxic activity was also evaluated against three strains of cancer cells, but none of the derivatives showed activity.

Chemical profile and antioxidant capacity verification of Psidium guajava (Myrtaceae) fruits at different stages of maturation.

Psidium guajava (Myrtaceae), a common plant in Cariri region, Ceara, Brazil, as well as in various parts of the world, contains high concentrations of bioactive compounds and in many communities its parts are used for therapeutic purposes. Studies describe antioxidant, antimicrobial and anti-diarrheal actions from extracts obtained from leaves, but information about the activities of the fruits and comparison of these at different maturity stages (immature, partially mature and mature) are scarce. This study aims to evaluate the antioxidant properties by quantifying the levels of phenolic and flavonoid compounds, carotenoids and vitamin C of P. guajava fruits at different stages of maturation. The content of phenolic compounds for the immature fruit, partially mature and mature were: 22.41; 34.61 and 32.92 mg of AG/g fraction. The flavonoid content for immature fruits, intermediate and mature were: 2.83; 5.10 and 5.65 mg RUT/g fraction, respectively. Following the same standards of maturation stages, the ascorbic acid content was determined with values of 0.48; 0.38 and 0.21 mg AA/g fraction, respectively. HPLC analysis identified and quantified the presence of gallic acid, catechin, chlorogenic acid, caffeic acid, epicatechin, rutin, quercitrin, isoquercitrin, quercetin, kaempferol, glycosylated campeferol, tocopherol, ß-carotene and lycopene. The antioxidant activity carried out by DPPH method showed the mature fruits bearing the best results, whereas chelation of Fe2+ ions showed higher percentage for the immature fruit. The results obtained by lipidic peroxidation were not satisfactory.

Chemical composition, antibacterial and antifungal activities of essential oil from Cordia verbenacea DC leaves.

BACKGROUND: Cordia verbenacea is a Brazilian coastal shrub popularly known as "erva baleeira". The essential oil from fresh leaves was obtained by hydrodistillation and analyzed by CG/MS. The main components were identified as ß-caryophyllene (25.4%), bicyclogermacrene (11.3%), δ-cadinene (9.%) and α-pinene (9.5%). In this study, the antimicrobial activity of Cordia verbenacea was evaluated. MATERIALS AND METHODS: The minimal inhibitory concentration (MIC) of the essential oil was obtained using the broth microdilution assay (from 512 to 8 µg/ml). RESULTS: The results showed that the essential oil presented fungistatic activity against Candida albicans and Candida krusei and antibacterial activity against Gram-positive strains (Staphylococcus aureus and Bacillus cereus) and against multiresistant Gram-negative (Escherichia coli 27), in all tests the MIC was 64 µg/ml. When the essential oil was associated to aminoglycosides (subinhibitory concentrations, MIC/8), a synergic and antagonic activity was verified. The synergic effect was observed to the amikacin association (MIC reduction from 256 mlto 64 µg/ml) in all strains tested. CONCLUSION: The essential oil of Cordia verbenacea influences the activity of antibiotics and may be used as an adjuvant in antibiotic therapy against respiratory tract bacterial pathogens.