In the Myrtaceae family, the species Eugenia involucrata DC., popularly known as "cerejeira-do-mato", is traditionally used for the antidiarrheal and digestive action of its leaves. However, no studies were found in the literature regarding its antimicrobial and antioxidant potential. In this context, the objective of the present study was to determine the chemical composition by gas chromatography coupled to mass spectrometry (GC-MS) to evaluate the antimicrobial activity by the broth microdilution technique and the antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazila (DPPH) method of the essential oil of E. involucrata leaves. GC-MS identified 28 compounds, all sesquiterpenes, corresponding to 89.41% of the essential oil. The antimicrobial activity of the essential oil was observed for all Gram-positive bacteria tested (Staplylococcus epidermidis, Enterococcus faecalis, Bacillus subtilis and Staplylococcus aureus) and for yeast Candida albicans. The essential oil presented a reduction capacity of DPPH up to 66.81%, evidencing its antioxidant potential. It is suggested that the antimicrobial and antioxidant action of E. involucrata essential oil is related to the presence of the major compounds, elixene (26.53%), β-caryophyllene (13.16%), α-copaene (8.41%) and germacrene D (7.17%).

SUMMARY The present study aimed to identify and quantify the components of the essential oil of Zanthoxylum caribaeum and to evaluate the antimicrobial potential of different plant extracts and the essential oil of this plant against different serotypes of Salmonella enterica, which is of greater occurrence and isolated in the western region of Paraná, Brazil. The extraction of the essential oil was performed using Clevenger apparatus and the chemical composition was determined by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The extracts were obtained through different solvents (ethanol, methanol, hexane, acetone, dichloromethane, ethyl acetate and distilled water). The antibacterial activity was carried out according to the broth microdilution technique. The GC-MS analysis resulted in the identification of 15 main components, all terpenes, representing 63.88% of the total essential oil. The major compounds identified were Germacrene-D (20.77%), a-Panasinsene (14.40 %) and b-Selinene (11.68 %). The essential oil presented antibacterial activity against 5 serotypes of Salmonella enterica, with MIC and MBC ranging from 7000 to 437 μg.mL-1. While MIC and MBC from the range from 200 to 25 mg.mL-1, being effective to most serotypes of S. enterica, with the exception of the aqueous extract. The results suggest that the essential oil and leaf extracts of Z. caribaeum represent an alternative for the control of S. enterica in the poultry sector, in this way reflecting a new perspective for studies with natural products.

The secondary metabolism products of plants have influenced great economic interest, given their chemical diversity and biological activities. Because of this, this study evaluates the phytochemical composition, antimicrobial activity, insecticidal, and antioxidant activity of plant extracts and oil of Myrcia oblongata. Saponins, steroids, triterpenoids, tannins, and flavonoids were detected. The extracts showed antimicrobial capacity on the tested microorganisms, except for the methanolic extract, which showed no activity for P. mirabilis and S. enteritidis. Regarding the analysis of antioxidant compounds, the hexanic, ethyl acetate and acetone extracts showed higher antioxidant activities and also higher insecticidal performance on Alphitobius diaperinus larvae, resulting in 80% adult mortality. The results reported here show that there may be a relationship between antioxidant potential and the insecticidal effect of Myrcia oblongata DC. The components present in both the extract and the oil can be used as natural alternative to synthetic compounds in the biological control of parasites and pathogenic microorganisms.

The Brazilian flora is known for its vast biodiversity; however, many species have been still little studied regarding to their chemical composition and biological potential. Thus, this study aimed to determine the antimicrobial, antioxidant and acaricidal activity of the extracts of leaves of Zanthoxylum caribaeum L. In addition, phytochemical screening of these extracts was carried out to determine the main classes of secondary metabolites present in Z. caribaeum.  Using the Z. caribaeum leaves, the aqueous extract and extracts were obtained in organic solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The antimicrobial activity of extracts was determined by broth microdilution method, and to detect antioxidant activity the method of capturing the free radical 2,2-diphenyl-1-picryl hydrazyl (DPPH) was used. The acaricidal activity of the extracts was tested on Dermanyssus gallinae (De Geer) (Acari: Dermanissidae). Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans. The ethanolic extract presented high free radical sequestration potential (71.2%) and antioxidant capacity (the lowest IC50 value - 24.39 μg mL-1). The extracts obtained with methanol and acetone were the most promising. In general, phytochemical screening indicated the presence of steroids, flavanones, flavones, flavonols, saponins, tannins, triterpenoids and xanthones.

O Brasil apresenta a maior biodiversidade no mundo e neste contexto, suas espécies nativas tornam-se uma alternativa na busca por moléculas bioativas para bioprospecção de antimicrobianos e antioxidantes naturais. Pertencente à família Myrtaceae, a espécie Myrcia palustris DC, conhecida popularmente como pintagueira-do-mato, não apresenta estudos referente às suas atividades biológicas e composição química. Diante disso, o objetivo deste trabalho foi determinar a composição química do óleo essencial de M. palustris por cromatografia gasosa acoplada à espectrometria de massas (CG-EM), avaliar sua atividade antimicrobiana pela técnica de microdiluição em caldo e a atividade antioxidante pela técnica de 2,2-difenil-1-picril-hidrazila (DPPH). O rendimento total a partir da extração pela técnica de hidrodestilação do óleo essencial foi de 0,35%. A CG-EM revelou a presença de 28 compostos, sendo a maioria da classe dos sesquiterpenos. A atividade antimicrobiana foi observada para todas as bactérias Gram-positivas (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus) com exceção de Staphyloccocus epidermidis. Em relação às Gram-negativas, verificou-se atividade inibitória apenas para Shigella flexneri. Para levedura Candida albicans não foi observada atividade inibitória e nem fungicida. O óleo essencial apresentou capacidade de redução de radicais de DPPH até 82,81%, confirmando seu potencial antioxidante. Sugere-se que a ação antimicrobiana e antioxidante presentes no óleo essencial de M. palustris esteja relacionada à presença dos compostos majoritários α-Guaieno (25,89%), α-Bulneseno (13,39%) e β-Selineno (4,76%).

SUMMARY The aim of this work was to evaluate the antimicrobial activity of plant extracts Ocotea silvestris Vattimo-Gil and Ocotea diospyrifolia (Meisn.) Mez against 10 serotypes Salmonella enterica of poultry origin of the highest incidence in the western region of Paraná, as well as to perform the phytochemical screening of the compounds of the two species. After obtaining the aqueous extract and the organic extracts (ethyl alcohol, ethyl acetate and hexane) was determined Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) by technique microdilution broth. Phytochemical prospecting performed according to qualitative methodology of precipitation and colorimetry. The extracts presented inhibitory and bactericidal activity in different concentrations (200 to 25 mg.mL-1) against the serotypes of Salmonella, varying according to the solvent extractor. The ethyl acetate extract presented the best results, followed by the alcoholic, aqueous and hexane extract. It is noteworthy that studies of antimicrobial activity with vegetable extract within the genus Ocotea are scarce, however, the Lauraceae family presents significant biological activities, mainly related to its essential oils. Phytochemical prospecting detected the presence of steroids and alkaloids in both Ocotea species, which may justify the antimicrobial potential found for Salmonella serotypes. It is concluded that these plants represent an alternative for the control of Salmonella in the poultry sector, reflecting a new perspective for studies with natural products.

Thus, the bioguided purification led to the isolation and characterization of the following compounds: 6,8-dimethoxy-2-H-1-quinolin-2-one, 3-((1-methylciclopentil) amino) quinolin-2(1H)-one, 104-ozaxol [3,2-a] quinoline and Anthranilic acid and the evaluation of its possible neuroprotective activity, based on the results of antioxidant and anticholinergic activity, showed that the compounds individually present medium to low antioxidant activities and that the anticholinergic activity is lost as the putification progresses, the fractions being more active than the pure compounds.

The species Eugenia involucrata DC. is a plant native to Brazil and is traditionally used for intestinal problems, however, little research has documented about its biological potential and phytochemical profile. Thus, the objective of this study was to carry out preliminary phytochemical prospecting, antimicrobial and antioxidant potential of E. involucrata extracts. Using the E. involucrata leaves, aqueous and organic extracts were obtained using the following solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The phytochemical prospecting detected the presence of saponins, steroids, flavonoids and tannins in the extracts. Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans, with concentrations between 3.12 and 50 mg/mL. The ethanolic and metanolic extract presented high free radical sequestration potential (>90%). The methanol extract showed an IC50 value statistically equal to that found for the commercial antioxidant BHT (p <0.05). The crude extracts obtained with ethanol and methanol were the most promising. These results suggest that methanolic, ethanolic and aqueous extracts are a promising source of natural bioactive.