title: Isolation, structural determination and acute toxicity of pinnatoxins E, F and G.
abstract: Pinnatoxins and pteriatoxins are a group of cyclic imine toxins that have hitherto only been isolated from Japanese shellfish. As with other cyclic imine shellfish toxins, pinnatoxins cause rapid death in the mouse bioassay for lipophilic shellfish toxins, but there is no evidence directly linking these compounds to human illness. We have identified the known pinnatoxins A (1) and D (6), and the novel pinnatoxins E (7), F (8) and G (5), in a range of shellfish and environmental samples from Australia and New Zealand using LC-MS. After isolation from the digestive glands of Pacific oysters, the structures of the novel pinnatoxins were determined by mass spectrometry and NMR spectroscopy, and their LD(50) values were evaluated by ip administration to mice. Examination of the toxin structures, together with analysis of environmental samples, suggests that pinnatoxins F and G are produced separately in different dinoflagellates. Furthermore, it appears probable that pinnatoxin F (8) is the progenitor of pinnatoxins D (6) and E (7), and that pinnatoxin G (6) is the progenitor of both pinnatoxins A-C (1 and 2) and pteriatoxins A-C (3 and 4), via metabolic and hydrolytic transformations in shellfish.
authors.affiliation: Cawthron Institute, Private Bag 2, Nelson, New Zealand. andy.selwood@cawthron.co.nz
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Selwood
authors.forename: Christopher O
authors.initials: CO
authors.lastname: Miles
authors.forename: Alistair L
authors.initials: AL
authors.lastname: Wilkins
authors.forename: Roel
authors.initials: R
authors.lastname: van Ginkel
authors.forename: Rex
authors.initials: R
authors.lastname: Munday
authors.forename: Frode
authors.initials: F
authors.lastname: Rise
authors.forename: Paul
authors.initials: P
authors.lastname: McNabb
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000737:chemistry; D005399:Fishes; D006863:Hydrogen-Ion Concentration; D007928:Lethal Dose 50; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D015394:Molecular Structure; D010125:Ostreidae / Q000737:chemistry; D057096:Shellfish Poisoning; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*
chemical_list: D000470:Alkaloids; D013141:Spiro Compounds; C552838:pinnatoxin E; C552839:pinnatoxin F; C552840:pinnatoxin G