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Synthesis of 1-Substituted-£]-Carboline Derivatives as Potential Antitumor Agents; Constituents from Formosan Marine Sponge Cacospongia sp.Lin, Chun-Ling 08 February 2001 (has links)
Previously, the natural£]-carboline metabolites as potent antitumor and antival agents have spurred a great interest on the synthetic and pharmacological studies of£]-carboline derivatives. Herein, a simple synthetic method by the application of Pictet-Spengler reaction and DDQ oxidation allowed the preparation of 1-substituted£]-carboline derivatives. Compounds 88-91 were synthesized from tryptamine and N-substituted-3-carbazole carboxaldehyde via Pictet-Spengler cyclization. Then, oxidation of compounds 88-91 by DDQ provided compounds 92-95. Their structures were determined by spectroscopic methods. Biological screening revealed that compounds 88 and 93 possessed in vitro cytotoxicties against two tumor cell lines (KB, Hepa), respectively. The ED50 value of compound 88 showed cytotoxicities against Hepa (Human hepatoma) tumor cell lines were 1.12 £gg/ml. The ED50 value of compound 93 showed cytotoxicities against KB (Human oral epidermoid carcinoma) tumor cell lines were 0.48 £gg/ml.
On the other hand, the marine sponge Cacospongia sp. was collected along seashore area of Lan-Yu in Taiwan. Fractionation of the MeOH/CHCl3 extract by using silica gel column chromatography yielded a dauble bond isomer fasciculatin (97). The structure of 97 was identified by UV¡BIR¡BMS¡B1D and 2D NMR.
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Inhibiteurs du Quorum Sensing de Vibrio harveyi issus d'éponges de Polynésie française / Vibrio harveyi quorum sensing inhibitors from marine sponges of French polynesiaMai, Tepoerau 25 May 2016 (has links)
La résistance bactérienne induite par l’utilisation massive d’antibiotiques en aquaculture, conduit à la recherche de nouveaux modes de traitement, des traitements anti-virulents et non toxiques. Différentes stratégies sont étudiées parmi lesquelles l’inhibition d’un système de régulation : le quorum sensing. Vibrio harveyi est une bactérie pathogène en aquaculture qui régule sa bioluminescence et la production de protéines de virulence par l’intermédiaire du quorum sensing. L’étude des éponges Leucetta chagosensis, Dysidea sp. 2669 et Cacospongia sp. 2110 collectées en Polynésie française, a permis l’isolement de huit métabolites secondaires dont quatre nouveaux : l’isonaamine D, le bis-isonaamidine A-Zn, la leucettamine D et le tuamotuolol. Leurs effets et leurs modes d’action ont été évalués sur deux phénotypes contrôlés par le quorum sensing chez V. harveyi: la bioluminescence et la production de métalloprotéases. Trois molécules ont ainsi montré une activité inhibitrice du quorum sensing de V. harveyi : l’isonaamine D, l’isonaamidine A et l’ilimaquinone. / The bacterial resistance induced by the massive use of antibiotics in aquaculture, leads to the search for new treatment methods, anti-virulent and non-toxic treatments. Different strategies are studied among which the inhibition of a system of regulation: the quorum sensing. Vibrio harveyi is a pathogenic bacterium in aquaculture that regulates its bioluminescence and the production of virulence proteins through quorum sensing. The study of sponges Leucetta chagosensis, Dysidea sp. 2669 and Cacospongia sp. 2110 collected in French Polynesia, allowed the isolation of eight secondary metabolites including four new ones: isonaamine D, bis-isonaamidine A-Zn, leucettamine D and tuamotuolol. Their effects and their modes of action were evaluated on two phenotypes controlled by quorum sensing in V. harveyi: bioluminescence and production of metalloproteases. Three molecules have thus shown an inhibitory activity of the quorum sensing of V. harveyi: isonaamine D, isonaamidine A and ilimaquinone.
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