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p. 1-8
Jaine H. H. L. De Oliveira , Mirna H. R. Seleghim , Christoph Timm , Achim Grube , Matthias Köck , Gislene G.F. Nascimento , Ana Claudia T. Martins , Elissa G. O. Silva , Ana Olívia De Souza , Paulo R. R. Minarini , Fabio C. S. Galetti , Célio L. Silva , Eduardo Hajdu and Roberto G. S. Berlinck Received: 7 December 2005 / Accepted: 18 January 2006 / Published: 20 January 2006
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| Download PDF Full-text (51 KB) | Download XML Full-text Abstract: Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines.
p. 9-14
Received: 18 January 2006 / Accepted: 21 February 2006 / Published: 21 February 2006
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| Download PDF Full-text (148 KB) | Download XML Full-text Abstract: Manzamenones A~C (1~3) and E~F (5~6), unique oxylipin metabolites isolated from a marine sponge Plakortis sp., have been found to exhibit inhibitory activity against Tcell protein tyrosine phosphatase (TCPTP). The inhibitory activity of 2 and 5 against TCPTP was 4 times more potent than that against protein tyrosine phosphatase-1B (PTP1B).
p. 15-21
Received: 28 December 2005 / Accepted: 17 February 2006 / Published: 21 February 2006
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| Download PDF Full-text (91 KB) | Download XML Full-text Abstract: The effects of seven compounds 1-7, isolated from a tropical ascidian Lissoclinum cf. badium, on IL-8 production in PMA-stimulated HL-60 cells were examined. Lissoclibadins 2 (2) and 3 (3) and lissoclinotoxin F (5) increased the IL-8 production in a dose-dependent manner. Compounds 2 and 5 are structural isomers possessing dimeric structures of trans and cis-orientations, respectively, and showed a very similar activity on the induction of IL-8 levels. Compound 3 and lissoclinotoxin E (4) are also structural isomers having dimeric trans and cis-structures, respectively, but 4 did not induce the IL-8 production. Lissoclibadin 1 (1, trimeric compound) and two monomeric compounds (6 and 7) did not increase the IL-8 level. Therefore, the differences in their structures remarkably affected the IL-8 production activity, the inhibition of cell proliferation, and the survival of HL-60 cells. Lissoclibadin 2 was the most interesting compound of the seven metabolites tested in this study.
p. 22-27
Received: 20 January 2006 / Accepted: 21 February 2006 / Published: 21 February 2006
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| Download PDF Full-text (73 KB) | Download XML Full-text Abstract: Bioassay-guided isolation from the ethanol extract of a marine sponge Theonella sp. collected in Palau yielded bistheonellide A, which strongly inhibited the colony formation of Chinese hamster V79 cells (EC50 = 6.8 nM). Bistheonellide A is an actinpolymerization inhibitor and was suggested to control cytokine production. Therefore, we attempted to detect an effect of this compound on IL-8 production in PMA-stimulated HL- 60 cells. Interestingly, bistheonellide A did not modulate the production of IL-8 under cytotoxic concentrations as determined by LDH analysis. Although the correlation between the inhibition of microtubule assembly and the stimulation of IL-8 production has been observed for several compounds, the polymerization of actin was not related to an IL-8 production in the case of bistheonellide A. It will be suggested that the actin polymerization is not involved in the IL-8 production system.
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