title: Antiprotozoal steroidal saponins from the marine sponge Pandaros acanthifolium.
abstract: The chemical composition of the Caribbean sponge Pandaros acanthifolium was reinvestigated and led to the isolation of 12 new steroidal glycosides, namely, pandarosides E-J (1-6) and their methyl esters (7-12). Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. Like the previously isolated pandarosides A-D (13-16), the new compounds 1-12 share an unusual oxidized D-ring and a cis C/D ring junction. The absolute configurations of the aglycones were assigned by interpretation of CD spectra, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid methanolysates. The majority of the metabolites showed in vitro activity against three or four parasitic protozoa. Particularly active were the compounds 3 (pandaroside G) and its methyl ester (9), which potently inhibited the growth of Trypanosoma brucei rhodesiense (IC(50) values 0.78 and 0.038 microM, respectively) and Leishmania donovani (IC(50)'s 1.3 and 0.051 microM, respectively).
authors.affiliation: Department of Chemistry, Center of Marine Bioproducts (CEBIMAR), Loma y 37 Alturas del Vedado, C.P. 10400 Havana, Cuba.
authors.forename: Erik L
authors.initials: EL
authors.lastname: Regalado
authors.forename: Deniz
authors.initials: D
authors.lastname: Tasdemir
authors.forename: Marcel
authors.initials: M
authors.lastname: Kaiser
authors.forename: Nadja
authors.initials: N
authors.lastname: Cachet
authors.forename: Philippe
authors.initials: P
authors.lastname: Amade
authors.forename: Olivier P
authors.initials: OP
authors.lastname: Thomas
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D007893:Leishmania donovani / Q000187:drug effects; D008386:Marine Biology; D019906:Nuclear Magnetic Resonance, Biomolecular; D009792:Oceans and Seas; D010963:Plasmodium falciparum / Q000187:drug effects; D011161:Porifera / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D000981:Antiprotozoal Agents; D012503:Saponins; D013256:Steroids; C552141:pandaroside F; C552140:pandaroside G; C552142:pandaroside G methyl ester