Plants produce many compounds that are biologically active, either as part of their normal program of growth and development or in response to pathogen attack or stress. Traditionally, Anadenanthera colubrina, Commiphora leptophloeos and Myracrodruon urundeuva have been used by communities in the Brazilian Caatinga to treat several infectious diseases. The ability to impair bacterial adhesion represents an ideal strategy to combat bacterial pathogenesis, because of its importance in the early stages of the infectious process; thus, the search for anti-adherent compounds in plants is a very promising alternative. This study investigated the ability of stem-bark extracts from these three species to control the growth and prevent biofilm formation of Pseudomonas aeruginosa, an important opportunistic pathogen that adheres to surfaces and forms protective biofilms. A kinetic study (0–72 h) demonstrated that the growth of extract-treated bacteria was inhibited up to 9 h after incubation, suggesting a bacteriostatic activity. Transmission electron microscopy and fluorescence microscopy showed both viable and nonviable cells, indicating bacterial membrane damage; crystal violet assay and scanning electron microscopy demonstrated that treatment strongly inhibited biofilm formation during 6 and 24 h and that matrix production remained impaired even after growth was restored, at 24 and 48 h of incubation. Herein, we propose that the identified (condensed and hydrolyzable) tannins are able to inhibit biofilm formation via bacteriostatic properties, damaging the bacterial membrane and hindering matrix production. Our findings demonstrate the importance of this abundant class of Natural Products in higher plants against one of the most challenging issues in the hospital setting: biofilm resilience.

In most species of social insect the queen signals her presence to her workers via pheromones. Worker responses to queen pheromones include retinue formation around the queen, inhibition of queen cell production and suppression of worker ovary activation. Here we show that the queen signal of the Brazilian stingless bee Friesella schrottkyi is a mixture of cuticular hydrocarbons. Stingless bees are therefore similar to ants, wasps and bumble bees, but differ from honey bees in which the queen's signal mostly comprises volatile compounds originating from the mandibular glands. This shows that cuticular hydrocarbons have independently evolved as the queen's signal across multiple taxa, and that the honey bees are exceptional. We also report the distribution of four active queen-signal compounds by Matrix-assisted laser desorption/ionization (MALDI) imaging. The results indicate a relationship between the behavior of workers towards the queen and the likely site of secretion of the queen's pheromones.

Matrix assisted laser desorption ionization (MALDI) is a technique widely employed in the analysis of proteins and peptides, and nowadays it has also been applied to small molecules. There is little significant information regarding the in-source dissociation processes on MALDI for natural products. Twenty-six flavonoids (flavanones, flavones and flavonols) were analyzed by MALDI using different methods (with different matrices) and without matrix to comprehend the in-source reactions and establish good analysis methods for these compounds. Depending on the class, structure and the laser intensity applied, methoxylated flavonoid aglycones can eliminate methyl radicals (˙CH3) in the source, such as flavonols, but lithium 2,4-dihydroxybenzoate matrix suppresses the ˙CH3 eliminations and retro-Diels-Alder cleavages in the source. All of the flavonoid O-glycosides evaluated herein eliminated the sugar in source, even in the presence of the matrix, and its product radical ions ([M-H-sugar](-)˙) were observed in the negative mode. The flavone C-glycosides suffered intense dissociation, which was reduced by the addition of a matrix and the application of low laser intensity, mainly in the negative mode. Depending on the hydroxyl substituents, the [M-H-H](-)˙ ion was observed with variable relative intensity in the spectra.

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Phytochemical studies are seeking new alternatives to prevent or treat cancer, including different types of leukemias. Campomanesia adamantium, commonly known as guavira or guabiroba, exhibits pharmacological properties including antioxidant, antimicrobial, and antiproliferative activities. Considering the anticancer potential of this plant species, the aim of this study was to evaluate the antileukemic activity and the chemical composition of aqueous extracts from the leaves (AECL) and roots (AECR) of C. adamantium and their possible mechanisms of action. The extracts were analyzed by LC-DAD-MS, and their constituents were identified based on the UV, MS, and MS/MS data. The AECL and AECR showed different chemical compositions, which were identified as main compounds glycosylated flavonols from AECL and ellagic acid and their derivatives from AECR. The cytotoxicity promoted by these extracts were evaluated using human peripheral blood mononuclear cells and Jurkat leukemic cell line. The cell death profile was evaluated using annexin-V-FITC and propidium iodide labeling. Changes in the mitochondrial membrane potential, the activity of caspases, and intracellular calcium levels were assessed. The cell cycle profile was evaluated using propidium iodide. Both extracts caused concentration-dependent cytotoxicity only in Jurkat cells via late apoptosis. This activity was associated with loss of the mitochondrial membrane potential, activation of caspases-9 and -3, changes in intracellular calcium levels, and cell cycle arrest in S-phase. Therefore, the antileukemic activity of the AECL and AECR is mediated by mitochondrial dysfunction and intracellular messengers, which activate the intrinsic apoptotic pathway. Hence, aqueous extracts of the leaves and roots of C. adamantium show therapeutic potential for use in the prevention and treatment of diseases associated the proliferation of tumor cell.

Acute lymphoblastic leukemia in infants has a high mortality rate, especially in children under 1 year and those with T-cell derived lineage.

Leishmaniasis is one of the World's most problematic diseases in developing countries. Traditional medicines to treat leishmaniasis have serious side effects, as well as significant parasite resistance problems. In this work, two alkaloids 1 and 2 were obtained from Corydalis govaniana Wall and seven alkaloids 3-9, were obtained from Erythrina verna. The structures of the compounds were confirmed by mass spectrometry and 1D-and 2D-NMR spectroscopy. The leishmanicidal activity of compounds 1-9 against Leishmania amazonensis was tested on promastigote forms and cytotoxicity against J774 (macrophage cell line) was assessed in vitro. Compound 1 showed potent activity (IC 50 = 0.18 µg/mL), compared with OPEN ACCESSMolecules 2014, 19 5693 the standard amphotericin B (IC 50 = 0.20 µg/mL). The spirocyclic erythrina-alkaloids showed lower leishmanicidal activity than dibenzoquinolizine type alkaloids.