Bacterial infections cause thousands of deaths in the world every year. In most cases, infections are more serious because the patient is already weakened, and often, the bacteria are already resistant to the antibiotics used. Counterparting this negative scenario, the interest in medicinal plants as an alternative to the synthetic antimicrobial drugs is blossoming worldwide. In the present work, we identified the volatile compounds of ethanol extracts of Melissa officinalis, Mentha sp., Ocimum basilicum, Plectranthus barbatus, and Rosmarinus officinalis by gas chromatography/mass spectrometry (GC/MS). Also was evaluated antimicrobial activity of ethanol extracts against 6 bacteria of clinical interest, and was tested the interaction of these extracts with a commercial antibiotic streptomycin. Phytol was a compound identified in all extracts by GC/MS, being majoritary component in Plectranthus barbatus and Rosmarinus officinalis. The Gram-positive bacteria were more sensitive to ethanol extracts, and Plectranthus barbatus and Rosmarinus officinalis were the most active extracts. Ethanol extracts exhibited a synergetic effect with streptomycin. These results encourage additional studies, in order to evaluate the possibilities of using ethanol extracts of Lamiaceae family as natural source for antibacterial activity.

Ethanol extract (EE) and fractions obtained from the ripe fruits of Solanum lycocarpum were examined in order to determine their phenolic composition, antioxidant capacity, antibacterial activities and cytotoxic potential. High-performance liquid chromatography coupled with DAD analysis indicated that caffeic and chlorogenic acids were the main phenolic compounds present in the EE, dichloromethane (DCM) and ethyl acetate (Ac) fractions. The antioxidant activity assessed by the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radical was significantly more pronounced for DCM and Ac fractions than that of the commercial antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT). EE and fractions exhibited selective antibacterial activity against Gram-positive bacteria, especially the hexane (Hex) and DCM fractions. EE and fractions exhibited low toxicity towards the LLC-MK2 cell line, especially the Hex, DCM and Ac fractions. This work provides the knowledge of phenolic composition in the extract and fractions from the ripe fruits of S. lycocarpum and their antioxidant, antibacterial and cytotoxic activities.

Introduction:There are few studies reporting the antifungal activities of Lippia alba extracts. Methods: A broth microdilution assay was used to evaluate the antifungal effects of Lippia alba extracts against seven yeast species of Candida and Cryptococcus. The butanol fraction was investigated by gas chromatography-mass spectrometry. Results: The butanol fraction showed the highest activity against Candida glabrata. The fraction also acted synergistically with itraconazole and fl uconazole against C. glabrata. The dominant compounds in the butanol fraction were 2,2,5-trimethyl-3,4-hexanedione, 3,5-dimethyl-4-octanone and hexadecane. Conclusions: The butanol fraction may be a good candidate in the search for new drugs from natural products with antifungal activity.

Ethanol extract and fractions obtained from fresh and dry aerial parts of Lippia alba were examined in order to determine their phytochemical composition, antioxidant capacity and antibacterial activities. The ethanol extracts and fractions exhibited an antioxidant effect by the DPPH assay, especially samples of fresh plant. HPLC analysis of the ethyl acetate fractions identified the presence of phenolic acids and flavonoids. The ethanol extract and fractions showed activity against reference and multidrug-resistant strains of Staphylococcus aureus and Enterococcus faecalis (MIC range 2000-250 μg/mL). The hexane and dichloromethane fractions of fresh plant showed better activity against reference strains of Escherichia coli (MIC of 250 and 125 μg/mL, respectively), but all extracts and fractions were less active against multidrug-resistant strains of all the Gram-negative species evaluated. The results showed that the extract and fractions of L alba aerial parts showed antibacterial activity, even against multidrug-resistant Gram-positive bacteria, and antioxidant effect (DPPH assay).

Lippia alba, belonging to the Verbenaceae family, is one of the most commonly utilized medicinal plants in folk medicine. The allelopathic activity was assessed using seeds of Lactuca sativa (lettuce) and Allium cepa (onion) by assessing the growth of the radicle and hypocotyl. The tests showed allelopathic efficiency in inhibiting the growth of lettuce and onion seeds. The best results for allelopathic activity were presented by the dichloromethane (DCM) fraction of the fresh plant, which inhibited radicle (23.04-100% lettuce and 64.17-66.36% onion) and hypocotyl (16.77-100% lettuce and 65.10-69.43% onion) formation, and as well as the DCM fraction of the dry plant, which also inhibited radicle (30.74-82.83% lettuce and 63.50-93.67% onion) and hypocotyl (24.12-70% lettuce and 69.07-79.95% onion) formation. Based on these results, it was found that the aerial parts of L. alba are rich in bioactive substances, suggesting the possibility of using of L. alba as a natural herbicide.

RESUMO Staphylococcus aureus é uma das principais bactérias causadoras de infecções hospitalares apresentando resistência a várias classes de antibióticos. Assim, o trabalho teve como objetivo fazer a triagem fitoquímica e avaliar atividade antibacteriana do extrato etanólico e frações obtidos do fruto maduro de Solanum frente à bactéria gram positiva meticilina-resistente Staphylococcus aureus (MRSA). Para isto, os frutos maduros de Solanum INTRODUÇÃOA resistência das bactérias aos antibióticos representa um grave problema de saúde pública mundial, caracterizando uma das principais causas de infecções nosocomiais, gerando elevadas taxas de morbidade e mortalidade.1 Staphylococcus aureus é uma bactéria Gram positiva, que apresenta elevada incidência, tanto na comunidade quanto no ambiente hospitalar. Um dos mecanismos de resistência predominante nesta espécie é a produção de beta-lactamases, especialmente penicilinases, nos quais os principais alvos de degradações por estas enzimas são amoxicilina e meticilina. Esta bactéria pode desenvolver diversas infecções, tais como epiteliais, gastrointestinais, osteomelite, pneumonia, septicemia, bacteremia, miocardite e síndrome do choque tóxico 2 . Na busca de novas substâncias antimicrobianas que apresentem diferentes mecanismos de ações daqueles disponíveis atualmente no mercado, as plantas sintetizam uma variedade de substâncias bioativas, com propriedades antimicrobianas, que apresentam uma diversidade de estruturas químicas capazes de reconhecerem e se ligarem a alvos moleculares presentes em bactérias patogênicas 3 . Assim, o objetivo deste trabalho foi fazer uma triagem fotoquímica e avaliar a atividade antibacteriana in vitro do extrato etanólico e frações frente à bactéria Gram positiva meticilina-resistente Staphylococcus aureus (MRSA, na qual foi selecionada para este estudo devido a sua importância médica em prevalência nas infecções causadas por bactérias. MATERIAL E MÉTODOSos frutos maduros de Solanum sp. foram coletados, secados em estufa, triturados em moinho de facas e extraídos por percolação exaustiva com etanol P.A., obtendo-se o extrato etanólico. Este foi fracionado por partição com solventes de polaridades crescentes, obtendo-se as frações hexânica (HEX), diclorometano (DCM), acetato de etila (AC) e hidroetanólica (HE).4 As amostras foram submetidas à triagem fitoquímica para avaliar a

The species Solanum lycocarpum A. St. Hil., popularly known as the "fruit of the wolf", is widely distributed in the Brazilian Cerrado. The fruits are usually consumed 'in natura' or used in jellies, jams or pasta preparations. The objective of this study was to evaluate the allelopathic potential of ethanol extract and fractions obtained from ripe fruits of S. lycocarpum against seeds of onion and lettuce. The ethanol extract and fractions showed allelopathic potential, especially on the growth of radicle of Allium cepa (onion). The dichloromethane and hydroethanol fractions showed inhibitory activity on the growth of hypocotyl of lettuce in concentrations at 125 and 250 g/mL. The hydroethanol fraction inhibited growth of radicle of lettuce, at the three concentrations tested. At the concentration of 500 g/mL, the dichloromethane fraction inhibited the radicle of lettuce in 86%. The ethanol extract and fractions showed inhibitory activity on hypocotyl of onion, in concentration at 500 g/mL, and radicle at the three concentrations tested. The dichloromethane fraction showed better allelopathic activity on the growth of lettuce and onion seeds. These results should encourage additional studies of extract and fractions from the ripe fruits of S. lycocarpum for the isolation of bioactive compounds with allelopathic potential.Keywords: Solanum lycocarpum; ripe fruits; allelopathic. RESUMOA espécie Solanum lycocarpum A. St. Hil., popularmente conhecida como "frutodo-lobo", é amplamente distribuída no Cerrado brasileiro. Os frutos geralmente são consumidos 'in natura' ou utilizados em geleias, compotas ou na preparação de massas. O objetivo deste estudo foi avaliar o potencial alelopático do extrato etanólico e frações obtidas dos frutos maduros de S. lycocarpum sobre as sementes de alface e cebola. O extrato etanólico e frações apresentaram potencial alelopático, especialmente sobre o crescimento da radícula de Allium cepa (cebola). As frações diclorometânica e hidroetanólica inibiram o hipocótilo de alface nas concentrações de 125 e 250 g/mL. A fração hidroetanólica inibiu o crescimento da radícula de alface nas três concentrações testadas. Na concentração de 500 g/mL, a fração diclorometânica inibiu a radícula em 86%. O extrato etanólico e frações apresentaram atividade inibitória sobre o hipocótilo da cebola na concentração de 500 g/mL e da radícula nas três concentrações testadas. A fração diclorometânica apresentou maior atividade alelopática sobre o crescimento das sementes de alface e cebola. Estes resultados incentivam estudos adicionais com o extrato e as frações dos frutos maduros de S. lycocarpum para o isolamento de compostos bioativos com potencial alelopático.Palavras-chave: Solanum lycocarpum; frutos maduros; alelopático.

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