These results provide new insights into metazoan GST diversity and the biochemical mechanisms used by marine organisms to cope with their chemically
defended prey. (c) 2008 Elsevier Inc. All rights reserved.”
“Austroplenckia populnea (Celastraceae), known as “marmelinho do campo”, www.selleckchem.com/products/BEZ235.html is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial. antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried Out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-beta-(D-glucopyranoside) (3). This is the first time that the presence of compound
www.selleckchem.com/products/ly2835219.html 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC(50) values of 0.7 mu g mL(-1) and 5.5 mu g mL(-1), respectively, while amphotericin B showed an IC(50) value of 0.1 mu g mL(-1) against both microorganisms. Compounds 1-3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC(50) value of 52 mu g mL(-1), while compounds 2 and 3 displayed an IC(50) value of 18 mu g mL(-1). In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was
evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.”
“Gating of ion channels by ligands is fundamental to cellular function, and ATP serves as both an energy source and a signaling molecule that modulates Selleckchem Blebbistatin ion channel and transporter functions. The slowly activating K+ channel I-Ks in cardiac myocytes is formed by KCNQ1 and KCNE1 subunits that conduct K+ to repolarize the action potential. Here we show that intracellular ATP activates heterologously coexpressed KCNQ1 and KCNE1 as well as I-Ks in cardiac myocytes by directly binding to the C terminus of KCNQ1 to allow the pore to open. The channel is most sensitive to ATP near its physiological concentration, and lowering ATP concentration in cardiac myocytes results in I-Ks reduction and action potential prolongation. Multiple mutations that suppress I-Ks by decreasing the ATP sensitivity of the channel are associated with the long QT (interval between the Q and T waves in electrocardiogram) syndrome that predisposes afflicted individuals to cardiac arrhythmia and sudden death.