title: Plakortides M and N, bioactive polyketide endoperoxides from the Caribbean marine sponge Plakortis halichondrioides.
abstract: From a small specimen of the marine sponge Plakortis halichondrioides collected in Puerto Rico we have isolated the known unsaturated ester methyl (2Z,6R,8R,9E)-3,6-epoxy-4,6,8-triethyl-2,4,9-dodecatrienoate (1) along with the known cyclic peroxide plakortide F (2). In addition, the structures of two new polyketide endoperoxides, namely, plakortide O (3) and plakortide P (4), were fully characterized by spectroscopic and chemical methods. The absolute stereochemistry of plakortide O methyl ester (3a) has been determined by analysis of the (R)- and (S)-MTPA esters of the acyclic derivative 5 obtained by hydrogenolysis. Plakortide O (3) and plakortide P (4) exhibited potent cytotoxicity in the NCI human cancer screening program, whereas plakortide O methyl ester, 3a, displayed strong antimalarial activity against Plasmodium falciparum [corrected].
authors.affiliation: Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346.
authors.forename: María
authors.initials: M
authors.lastname: del Sol Jiménez
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Garzón
authors.forename: Abimael D
authors.initials: AD
authors.lastname: Rodríguez
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D017691:Caribbean Region; D004146:Dioxanes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D015394:Molecular Structure; D010963:Plasmodium falciparum / Q000187:drug effects; D011161:Porifera / Q000737:chemistry*; D011647:Puerto Rico; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000962:Antimalarials; D000970:Antineoplastic Agents; D004146:Dioxanes; C102699:plakortide F; C478200:plakortide M; C478201:plakortide N