New saxitoxin analogues from the freshwater filamentous cyanobacterium Lyngbya wollei

• Published in: Natural toxins Vol. 5; no. 4; p. 146
• Main Authors: Onodera, H, Satake, M, Oshima, Y, Yasumoto, T, Carmichael, W.W
• Format: Journal Article
• Language: English
• Published: United States 1997
• Subjects: Animals; Chromatography, High Pressure Liquid; Cyanobacteria - chemistry; CYANOPHYTA; ENVENENAMIENTO; Fresh Water; INTOXICATION; Lyngbya Toxins - isolation & purification; Lyngbya Toxins - toxicity; Magnetic Resonance Spectroscopy; Male; Mass Spectrometry; Mice; Mice, Inbred Strains; PARALYTIC SHELLFISH POISONING; POISONING; Saxitoxin - analogs & derivatives; Saxitoxin - isolation & purification; Saxitoxin - toxicity
• ISSN: 1056-9014; 1522-7189
• DOI: 10.1002/19970504NT4

Along with decarbamoylsaxitoxin and decarbamoylgonyautoxin-2 and -3, six new saxitoxin analogues were isolated from the freshwater mat-forming filamentous cyanobacterium Lyngbya wollei collected from Guntersville Reservoir on the Tennessee River in Alabama. Their structures were determined by electrospray ionization mass spectrometry and several NMR techniques. Five of the toxins contain an acetyl moiety attached to the side chain, which is the first report of these saxitoxin analogues. In three of the toxins a hydrated ketone at C-12 was reduced to alpha-alcohol. The presence of acetate in the side chain resulted in a sevenfold to 17-fold times decrease in mouse toxicity compared to their carbamoyl counterparts, while the reduction at C-12 resulted in a complete loss of mouse toxicity.