title: Halogenated fatty acid amides and cyclic depsipeptides from an eastern Caribbean collection of the cyanobacterium Lyngbya majuscula.
abstract: A lipophilic extract of an eastern Caribbean collection of Lyngbya majuscula yielded two new halogenated fatty acid amides, grenadamides B (1) and C (2), and two new depsipeptides, itralamides A (3) and B (4), along with the known compounds hectochlorin and deacetylhectochlorin. The recently reported depsipeptide carriebowmide (5) was also present in the extract and isolated as its sulfone artifact (6). Compounds 1-4 were identified by spectroscopic methods. The configurations of the amino acid residues of 3, 4, and 6 were determined by LC-MS analyses of diastereomeric derivatives of the acid hydrolysates (advanced Marfey's method). Based on the configurational analysis of 6, in direct comparison with authentic carriebowmide (5), a minor structural revision of 5 is proposed. Compounds 1 and 2 displayed marginal activity against the beet armyworm (Spodoptera exigua). Compounds 1-4 and 6 were assessed for general cell toxicity in human embryonic kidney (HEK293) cells. Only itralamide B (4) displayed significant cytotoxicity, showing an IC(50) value of 6 +/- 1 muM.
authors.affiliation: AgraQuest, Inc., Davis, CA 95618, USA.
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Jiménez
authors.forename: Tifanie
authors.initials: T
authors.lastname: Vansach
authors.forename: Wesley Y
authors.initials: WY
authors.lastname: Yoshida
authors.forename: Bryan
authors.initials: B
authors.lastname: Sakamoto
authors.forename: Peter
authors.initials: P
authors.lastname: Pörzgen
authors.forename: F David
authors.initials: FD
authors.lastname: Horgen
mesh_terms: D000577:Amides; D000818:Animals; D000458:Cyanobacteria / Q000737:chemistry; D047630:Depsipeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005260:Female; D019425:Grenada; D006801:Humans; D006846:Hydrocarbons, Halogenated / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007668:Kidney / Q000166:cytology / Q000187:drug effects; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018411:Spodoptera / Q000187:drug effects
chemical_list: D000577:Amides; D047630:Depsipeptides; D005231:Fatty Acids, Unsaturated; D006846:Hydrocarbons, Halogenated; C534638:carriebowmide; C544274:grenadamide B; C544275:grenadamide C; C544276:itralamide A; C544277:itralamide B; C087123:romidepsin