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Piplartine, an alkaloid produced by plants in the genus Piper, displays promising anticancer activity. Understanding the gas-phase fragmentation of piplartine by electrospray ionization tandem mass spectrometry can be a useful tool to characterize biotransformed compounds produced by in vitro and in vivo metabolism studies. As part of our efforts to understand natural product fragmentation in electrospray ionization tandem mass spectrometry, the gas-phase fragmentation of piplartine and its two metabolites 3,4-dihydropiplartine and 8,9-dihydropiplartine, produced by the endophytic fungus Penicillium crustosum VR4 biotransformation, were systematically investigated. Proposed fragmentation reactions were supported by ESI-MS/MS data and computational thermochemistry. Cleavage of the C-7 and N-amide bond, followed by the formation of an acylium ion, were characteristic fragmentation reactions of piplartine and its analogs. The production of the acylium ion was followed by three consecutive and competitive reactions that involved methyl and methoxyl radical eliminations and neutral CO elimination, followed by the formation of a four-member ring with a stabilized tertiary carbocation. The absence of a double bond between carbons C-8 and C-9 in 8,9-dihydropiplartine destabilized the acylium ion and resulted in a fragmentation pathway not observed for piplartine and 3,4-dihydropiplartine. These results contribute to the further understanding of alkaloid gas-phase fragmentation and the future identification of piplartine metabolites and analogs using tandem mass spectrometry techniques. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objetivos: Evaluar la actividad antimicrobiana del hidróxido de calcio en combinación con omeprazol, a diferentes concentraciones, frente a E. faecalis.Materiales y métodos: Estudio experimental in vitro en el que se probó la actividad antimicrobiana del hidróxido de calcio y de hidróxido de calcio más omeprazol en diferentes concentradones (1, 5, 8 y 10 %) frente a E. faecalis, determinando la sensibilidad antimicrobiana en cada uno de los grupos. El análisis estadístico de los datos se realizó mediante la prueba estadística Shapiro Wilk y luego se utilizó la prueba no paramétrica de U Mann-Whitney.Resultados: Se obtuvo una notable sensibilidad de la bacteria al omeprazol, la cual se incrementa a medida que se aumenta la concentración de omeprazol. El grupo de hidróxido de calcio con omeprazol al 10 % tuvo el mayor porcentaje de inhibición (87,7), luego al 8 % con (71,9), al 5 % (67,8) y al 1 % (64,1).Conclusiones: Hay un notable incremento de la actividad antimicrobiana de hidróxido de calcio combinado con omeprazol frente a Enterococcus faecalis.

Molecular Modeling is an important tool in drug design and it is very useful to predict biological activity from a library of compounds. A wide variety of computer programs and methods have been developed to visualize the tridimensional geometry and calculate physical properties of drugs. In this work, we describe a practical approach of molecular modeling as a powerful tool to study structure-activity relationships of drugs, including some antibacterials, hormones, cholinergic and adrenergic agents. At first, the students learn how to draw 3D structures and use them to perform conformational and molecular analysis. Thus, they compare drugs with similar pharmacological activity by superimposing one structure on the top of another and evaluate the geometry and physical properties.

The methanol extract of stems of Trichilia claussenii yielded three new sesquiterpenoids: 14-hydroxyelemol, germacra-10(14)-en-9,11,15-triol and germacra-3,10(14)-dien-9,11-diol-4-carbaldehyde. Two known sesquiterpenoids beta-eudesmol, cryptomeridiol and the triterpenoid 22,25-dihydroxy-9beta,19-cyclolanost-23-en-3-one were also isolated. The dichloromethane extract from the leaves of T. lepidota afforded a mixture of hydrocarbons (C29H60, C31H64 and C33H68), a mixture of the sesquiterpenes caryophyllene and humulene epoxides, spathulenol, and a series of sterols: 24-methylene-12b-hydroxycholesterol, 24-methyl-12beta-hydroxycholest-4-en-3-one, 24-methylene-12beta-hydroxycholest-5-ene-3-palmitate; a mixture of 24-methylenecholesterol, campesterol, stigmasterol and beta-sitosterol; besides alpha-tocoferol and phytol. From the methanol extract it was isolated N-methyl-4-hydroxyproline. The structures of the isolated compounds were determined on the basis of spectroscopic analysis.

The most accepted hypothesis for Diseases Hemorragic Fever/Dengue Shock Syndrome (DHF/ DSS) pathogenesis is a phenomenon known as Antibody Dependent Enhancement (ADE). MAbs are a useful and sensitive tool for ADE studies. The majority of monoclonal antibodies, which have been used to report ADE activity, recognise epitopes on surface glycoproteins; two of these proteins have been E and prM. A mouse monoclonal antibody specific (MAb 4B6) to a recombinant envelope protein (E) from dengue virus type 4 expressed in Pichia pastoris was studied for ADE of infection in P388D1, mouse macrophage like cells. This study was performed using a viral multiplicity of m=0,1, MAb dilutions to 10-3 to 10-6 and dengue 2 and dengue 4 strains. Our 4B6 monoclonal antibody neutralized homologous virus but it did not enhance it The neutralization and non amplifying characteristic of 4B6 MAb are similar in pattern to others. MAb mimic peptides, chimeric and fusion proteins containing the epitopes for neutralizing and no amplificating Mab could be used as a good subunit candidates for a future dengue vaccines.The fact that this Mab did not revealed the presence of enhancement epitopes in E Dengue 4 recombinant protein suggest that one as an attractive antigen in immunoprotection studies. [ABSTRACT FROM AUTHOR]