Vitex megapotamica (Sprengel) Moldenke belongs to the Verbenaceae family and is popularly known as "tarumã". The antioxidant capacity of fractions and crude extract from the leaves of V. megapotamica were determined in this study through the capacity to remove reactive species and phenolic compounds were quantified in the various fractions. The IC 50 (DPPH) ranged from 14.17 ± 0.76 to 37.63 ± 0.98 µg/mL. The ethyl acetate fraction might contain the strongest lipid peroxidation inhibitory compounds with an IC 50 of 16.36 ± 5.09 µg/mL, being also the one with the highest content of polyphenols (522.4 ± 1.12 mg/g), flavonoids (220.48 ± 0.30 mg/g) and condensed tannins (3.86 ± 0.53 mg/g). Compounds quantified by HPLC/DAD in the crude extract and fractions were chlorogenic and rosmarinic acids. Higher dosages of the extracts were more effective in reducing levels of plasma protein carbonyls and were also shown to be able to remove reactive species by a 2',7'-dichlorofluorescein diacetate assay, reducing oxidative OPEN ACCESSMolecules 2013, 18 8343 stress in all tested fractions. Results obtained indicated that V. megapotamica exhibits good potential to prevent diseases caused by the overproduction of free radicals and it might also be used as a potential source of natural antioxidant agents.

The main objective of this study was to demonstrate the antimicrobial potential of the crude extract and fractions of Chenopodium ambrosioides L., popularly known as Santa-Maria herb, against microorganisms of clinical interest by the microdilution technique, and also to show the chromatographic profile of the phenolic compounds in the species. The Phytochemical screening revealed the presence of cardiotonic, anthraquinone, alkaloids, tannins and flavonoids. The analysis by HPLC–DAD revealed the presence of rutin in the crude extract (12.5 ± 0.20 mg/g), ethyl acetate (16.5 ± 0.37 mg/g) and n-butanol (8.85 ± 0.11 mg/g), whereas quercetin and chrysin were quantified in chloroform fraction (1.95 ± 0.04 and 1.04 ± 0.01 mg/g), respectively. The most promising results were obtained with the ethyl acetate fraction, which inhibited a greater number of microorganisms and presented the lowest values of MIC against Staphylococcus aureus and Enterococcus faecalis (MIC = 0.42 mg/mL), Pseudomonas aeruginosa (MIC = 34.37 mg/mL), Paenibacillus apiarus (MIC = 4.29 mg/mL) and Paenibacillus thiaminolyticus (MIC = 4.29 mg/mL). Considering mycobacterial inhibition, the best results were obtained by chloroform fraction against M. tuberculosis, M. smegmatis, and M. avium (MIC ranging from 156.25 to 625 μg/mL). This study proves, in part, that the popular use of C. ambrosioides L. can be an effective and sustainable alternative for the prevention and treatment of diseases caused by various infectious agents.

a b s t r a c tIntroduction: Free radicals induce numerous diseases by lipid peroxidation, protein peroxidation, and DNA damage. It has been reported that numerous plant extracts have antioxidant activities to scavenge free radicals. In this present study we determined the in vitro antioxidant capacity and quantified of total phenolics, flavonoids, tannins and alkaloids of Tabernaemontana catharinensis crude extract and fractions leaves. Methods: The antioxidant potential was evaluated by 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging and thiobarbituric acid reactive species (TBARS) methods, total phenolics content was determined using the FolineCiocalteu assay, flavonoids, tannins and alkaloids were determined by spectrophotometer. Results: Crude extract and fractions showed inhibition against TBARS, ethyl acetate was the most effective fraction (IC 50 ¼ 6.71 AE 0.19 mg/mL), subsequently by butanolic (26.15 AE 0.08 mg/mL), dichloromethane (43.25 AE 0.12 mg/mL) and crude extract (61.09 AE 0.05 mg/mL), respectively. Moreover, the DPPH assay, presented IC 50 value ranged of 4.64 AE 1.25 to 27.78 AE 0.93 mg/mL. Contents of total phenols, flavonoids, tannins and alkaloids of T. catharinensis followed the order: ethyl acetate > butanolic > dichloromethane fractions > crude extract. Conclusion: The present study, we found that the crude extract and fractions of T. catharinensis showed good antioxidant activity. Among the samples tested, the ethyl acetate fraction showed better activity than others.

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The antioxidant capacity of the crude extract and fractions of Tabernaemontana catharinensis fruits and branches, was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and the content of polyphenols, flavonoids, alkaloids and condensed tannins were determined by the spectrophotometric method. The ethyl acetate fraction of the fruits and the n-butanol fraction of the branches showed IC 50 of 181.82 µg/mL and 78.19 µg/mL, respectively. All fractions were analyzed by high performance liquid chromatography (HPLC), in the branches were quantified chlorogenic acid in the chloroform (8.96 mg/g), ethyl acetate (4.31 mg/g) and n-butanol (3.33 mg/g) fractions; caffeic acid in the ethyl acetate (5.24 mg/g) and n-butanol (1.81 mg/g); gallic acid (0.52 mg/g) in the n-butanol. In the fruits, chlorogenic acid in the chloroform (1.67 mg/g); rutin in the ethyl acetate (3.45 mg/g) and n-butanol (8.98 mg/g) fractions.The present study showed that these quantified compounds can contribute to antioxidant capacity which was higher in the branches than in the fruits.

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The volatile oil from the stem bark of Scutia buxifolia (Rhamnaceae) has been obtained by hydrodistillation and analyzed by GC-MS. Twenty-one components were identified representing 99.93 % of the total oil composition, spathulenol (35.87%), β-cubebene (17.26%), germacrene D (6.43%), linalool (5.19%), carvacrol (4.05%) were the main components of S. buxifolia essential oil. Antioxidant and antimicrobial properties of the essential oil were evaluated by free radical scavenging (DPPH) assay and micro broth dilution method, respectively. S. buxifolia essential oil presented interesting radical scavenging activity (IC 50 = 15.03 ± 0.11 μg/mL). The antibacterial assay showed that S. buxifolia stem bark essential oil was moderately active against the Staphylococcus aureus and Micrococcus sp. (MIC = 500 μg/mL) and Escherichia coli (250 μg/mL). To the best of our knowledge, this is the first study on the composition, antioxidant and antimicrobial activities of essential oil from the S. buxifolia collected from Brazil.