In vitro antiparasitic activity and chemical composition of the essential oil from Protium ovatum leaves (Burceraceae)

ABSTRACT Leishmaniasis and trypanosomiasis are globally widespread parasitic diseases which have been responsible for high mortality rates. Since drugs available for their treatment are highly hepatotoxic, nephrotoxic and cardiotoxic, adherence to therapy has been affected. Thus, the search for new, more effective and safer drugs for the treatment of these diseases is necessary. Natural products have stood out as an alternative to searching for new bioactive molecules with therapeutic potential. In this study, the chemical composition and antiparasitic activity of the essential oil from Protium ovatum leaves against trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania amazonensis were evaluated. The essential oil was promising against trypomastigote forms of T. cruzi (IC50= 28.55 μg.mL-1) and L. amazonensis promastigotes (IC50 = 2.28 μg.mL-1). Eighteen chemical constituents were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS) in the essential oil, whose major constituents were spathulenol (17.6 %), caryophyllene oxide (16.4 %), β-caryophyllene (14.0 %) and myrcene (8.4 %). In addition, the essential oil from P. ovatum leaves had moderate cytotoxicity against LLCMK2 adherent epithelial cell at the concentration range under analysis (CC50 = 150.9 μg.mL-1). It should be highlighted that this is the first report of the chemical composition and anti-Trypanosoma cruzi and anti-Leishmania amazonensis activities of the essential oil from Protium ovatum leaves.

Chemical composition, antioxidant and antibacterial activities of essential oils from leaves and flowers of Eugenia klotzschiana Berg (Myrtaceae)

ABSTRACT Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal bacteria and antioxidant properties. Eugenia klotzschiana Berg (pêra-do-cerrado, in Portuguese) is a species of Myrtaceae with restricted distribution in the Cerrado. The essential oils were extracted through the hydrodistillation technique using a modified Clevenger apparatus (2 hours) and chemically characterized by GC-MS. The major compounds were α-copaene (10.6 %) found in oil from leaves in natura, β-bisabolene (17.4 %) in the essential oil from dry leaves and α-(E)-bergamotene (29.9 %) in oil from flowers. The antioxidant activity of essential oils showed similarities in both methods under analysis (DPPH and ABTS˙+) and the results suggested moderate to high antioxidant activity. The antibacterial activity was evaluated by determining minimum inhibitory concentrations (MICs), using the microdilution method. MIC values below 400 µg/mL were obtained against Streptococcus salivarius (200 µg/mL), S. mutans (50 µg/mL), S. mitis (200 µg/mL) and Prevotella nigrescens (50 µg/mL). This is the first report of the chemical composition and antibacterial and antioxidant activities of the essential oils of E. klotzschiana. These results suggest that E. klotzschiana, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Cornoside and other constituents from the latex of Parahancornia amapa (Hub. ) Ducke (Apocynaceae) a medicinal plant in Northern Brazil / Cornosídeo e outros constituintes do látex de Parahancornia amapa (Hub. ) Ducke (Apocynaceae) uma planta medicinal no Norte do Brasil

Latex of Parahancornia amapa which is known as "amapa milk" in folk medicine was extracted with hexane, dichloromethane and methanol. From the hexane and dichloromethane were identified mixtures of 3-O-acyl lupeol esters such as identified previously. In the methanol extract, a large amount of carbohydrates, the phenylethanoid glucoside known as cornoside, other phenylethanoids derivatives and methylmyoinositol were identified. The analysis of IR, NMR and GC-LRMS of the natural compounds and tetra-acetylcornoside and comparison with literature data were used to identify the compounds.

O látex de Parahancornia amapa, popularmente conhecido como "leite do amapá" foi extraído com hexano, diclorometano e metanol. As frações obtidas com hexano e diclorometano forneceram misturas de 3-O-acil-lupeol e triterpenos confirmando resultados de estudos já realizados. No extrato metanólico identificou-se uma grande quantidade de mistura de carboidratos, metilmioinositol e derivados de feniletanóides tendo como principal constituinte o cornosídeo. Estes constituintes foram identificados através da análise de espectros de IV, RMN ¹H e 13C e CG-EM das frações e do derivado acetilado do cornosídeo e do metilmioinositol.

Metabólitos especiais isolados de Laseguea erecta (Apocynaceae) / Special metabolites isolated from Laseguea erecta (Apocynaceae)

Do caule de Laseguea erecta foram isolados o lupeol, a cumarina escopoletina, o lignóide pinoresinol e o glicosil-cardenoídeo, alfa-L-tevetosil-digitoxigenina. As estruturas foram identificadas com o uso de técnicas espectroscópicas de IV, RMN ¹H e 13C, incluindo técnicas especiais 1D e 2D, espectroscopia de massas e comparação com dados da literatura.

From the stem of Laseguea erecta the triterpene lupeol, the cumarine scopoletin, the lignoid pinoresinol and digitoxigenin alpha-L-tevetoside, known as thevetioside, were isolated. The structures were identified by IR, mass, ¹H and 13C NMR spectroscopy, including 1D and 2D techniques, together with comparison with literature data.