title: Isoswinholide B and swinholide K, potently cytotoxic dimeric macrolides from Theonella swinhoei.
abstract: Chemical investigation of an Indonesian specimen of Theonella swinhoei afforded the new dimeric macrolides isoswinholide B (5) and swinholide K (6), along with the known swinholides A (1), B (2) and D (3) and isoswinholide A (4). Isoswinholide B showed an unprecedented 21/19' lactonization pattern, while swinholide K included an sp(2) methylene attached at C-4 and an additional oxymethine group at C-5, whose configuration has been determined through application of J-based configuration analysis. The isolated swinholides (1-6), with the exception of isoswinholide B, showed a cytotoxic activity on HepG2 (hepatocarcinoma cell line) in the nanomolar range.
authors.affiliation: Dipartimento di Farmacia, Università di Napoli 'Federico II', Via D. Montesano 49, 80131 Napoli, Italy.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Sinisi
authors.forename: Barbara
authors.initials: B
authors.lastname: Calcinai
authors.forename: Carlo
authors.initials: C
authors.lastname: Cerrano
authors.forename: Henny A
authors.initials: HA
authors.lastname: Dien
authors.forename: Angela
authors.initials: A
authors.lastname: Zampella
authors.forename: Claudio
authors.initials: C
authors.lastname: D'Amore
authors.forename: Barbara
authors.initials: B
authors.lastname: Renga
authors.forename: Stefano
authors.initials: S
authors.lastname: Fiorucci
authors.forename: Orazio
authors.initials: O
authors.lastname: Taglialatela-Scafati
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D019281:Dimerization; D056945:Hep G2 Cells; D006801:Humans; D018942:Macrolides / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D009682:Magnetic Resonance Spectroscopy; D008387:Marine Toxins / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D008968:Molecular Conformation; D047232:Theonella / Q000737:chemistry*
chemical_list: D018942:Macrolides; D008387:Marine Toxins; C586731:isoswinholide B; C068192:swinholide B
keywords: Actin-binding cytotoxins; Macrolides; Swinholides; Theonella swinhoei