Taveuniamides: new chlorinated toxins from a mixed assemblage of marine cyanobacteria

• Published in: Tetrahedron Vol. 60; no. 33; pp. 7025 - 7033
• Main Authors: Williamson, R.Thomas, Singh, Inder Pal, Gerwick, William H.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 09.08.2004; Elsevier
• Subjects: Chemistry; Chemistry, Organic; Dichloroenyne; Lyngbya majuscula; Physical Sciences; Science & Technology; Taveuniamide; Lyngbya majuscula; Taveuniamide; Dichloroenyne; METABOLITES; LYNGBYA-MAJUSCULA; taveuniamide; NATURAL-PRODUCTS; CONFIGURATION; BARBAMIDE; ANTILLATOXIN; COUPLING-CONSTANTS; BRINE SHRIMP; CURACIN-A; lyngbya majuscula; dichloroenyne; ICHTHYOTOXIC CYCLIC LIPOPEPTIDE
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2004.02.076

Brine shrimp toxicity guided fractionation of the extracts from two mixed Fijian collections of the cyanobacteria Lyngbya majuscula and Schizothrix sp. led to the isolation of eleven novel chlorinated lipids. All of these metabolites show an intriguing constellation of unsaturation (olefinic and acetylenic bonds) and chlorination at the two termini of a 15-carbon chain. The central carbon atom of the chain (C-8) is substituted in each case with an N-acetate function. Taveuniamides A–E have an adjacent carbomethoxy group at C-9 to form a protected β-amino acid while taveuniamides F–K have a methylene group at this position. A standard assortment of 2D NMR techniques in concert with mass spectrometry and other analytical techniques were used to define the structures of these novel metabolites. Taveuniamides F, G and K were the most potent brine shrimp toxins with LD 50s between 1.7–1.9 μg/mL. Graphic