title: Netamines O-S, Five New Tricyclic Guanidine Alkaloids from the Madagascar Sponge Biemna laboutei, and Their Antimalarial Activities.
abstract: In our continuing program to isolate new compounds from the Madagascar sponge Biemna laboutei, five new tricyclic guanidine alkaloids, netamines O - S (1-5, resp.), have been identified together with the known compounds netamine E (6) and mirabilin J (7). The structures of all new netamines were assigned on the basis of spectroscopic analyses. Their relative configurations were established by analysis of ROESY data and comparison with literature data. Netamines O, P, and Q, which were isolated in sufficient quantities, were tested for their cytotoxic activities against KB cells and their activities against the malaria parasite Plasmodium falciparum. Netamines O and Q were found to be moderately cytotoxic. Netamines O, P, and Q exhibited antiplasmodial activities with IC₅₀ values of 16.99 ± 4.12, 32.62 ± 3.44, and 8.37 ± 1.35 μM, respectively.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Faculté des Sciences et Technologies, Université de La Réunion, 15 Avenue René Cassin, CS 92003, FR-97744 Saint-Denis Cedex 9, La Réunion, (phone: +262-262-938197; fax: +262-262-938183).
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Gros
authors.affiliation: Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, UPR 2301, CNRS, Avenue de la Terrasse, FR-91198 Gif-sur-Yvette.
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Martin
authors.affiliation: Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, UPR 2301, CNRS, Avenue de la Terrasse, FR-91198 Gif-sur-Yvette.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sorres
authors.affiliation: Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, UPR 2301, CNRS, Avenue de la Terrasse, FR-91198 Gif-sur-Yvette.
authors.forename: Céline
authors.initials: C
authors.lastname: Moriou
authors.affiliation: Aix Marseille Université, CNRS, IRD, Avignon Université, IMBE UMR 7263, Station marine d'Endoume, FR-13397 Marseille.
authors.forename: Jean
authors.initials: J
authors.lastname: Vacelet
authors.affiliation: Laboratory of Pharmacognosy, Department of Pharmacy, CIRM, University of Liège B36, BE-4000 Liège.
authors.forename: Michel
authors.initials: M
authors.lastname: Frederich
authors.affiliation: Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Faculté des Sciences et Technologies, Université de La Réunion, 15 Avenue René Cassin, CS 92003, FR-97744 Saint-Denis Cedex 9, La Réunion, (phone: +262-262-938197; fax: +262-262-938183).
authors.forename: Maurice
authors.initials: M
authors.lastname: Aknin
authors.affiliation: School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Kashman
authors.affiliation: Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Faculté des Sciences et Technologies, Université de La Réunion, 15 Avenue René Cassin, CS 92003, FR-97744 Saint-Denis Cedex 9, La Réunion, (phone: +262-262-938197; fax: +262-262-938183). anne.bialecki@univ-reunion.fr.
authors.forename: Anne
authors.initials: A
authors.lastname: Gauvin-Bialecki
authors.affiliation: Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, UPR 2301, CNRS, Avenue de la Terrasse, FR-91198 Gif-sur-Yvette.
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Mourabit
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006146:Guanidines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008270:Madagascar; D008968:Molecular Conformation; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects*; D011161:Porifera / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000470:Alkaloids; D000962:Antimalarials; D006146:Guanidines
keywords: Antiplasmodial activity; Biemna laboutei; Cytotoxic activity; Guanidine alkaloids; Netamines O - S