Isolation of pectenotoxin-2 from Dinophysis acuta and its conversion to pectenotoxin-2 seco acid, and preliminary assessment of their acute toxicities.
We have developed a simple and effective method for isolating pectenotoxin-2 (PTX-2) from Dinophysis cells collected from a natural bloom. A two-step extraction procedure followed by two column chromatography steps produced PTX-2 in high purity suitable for use as an analytical standard and for toxicological studies. Incubation of purified PTX-2 with the supernatant from ultracentrifuged blue (Mytilus edulis) or Greenshell (Perna canaliculus) mussel hepatopancreas homogenate caused rapid conversion to pectenotoxin-2 seco acid (PTX-2 SA). Purification of PTX-2 SA was achieved by solvent extraction followed by column chromatography. PTX-2 and PTX-2 SA were fully characterized by LC-MS and NMR, and full (1)H and (13)C NMR assignments were obtained. Okadaic acid C(8)-diol ester was isolated during the purification of PTX-2, and its identity confirmed by NMR and LC-MS analyses. Pectenotoxin-2 seco acid methyl ester, identified by LC-MS, was also produced during the hydrolytic procedure due to the presence of methanol. PTX-2 was acutely toxic to mice by i.p. injection (LD(50)=219 microg/kg) but no effects were seen with PTX-2 SA at 5000 microg/kg. Neither PTX-2 nor PTX-2 SA was overtly toxic to mice by the oral route at doses up to 5000 microg/kg. No diarrhea was observed in mice dosed with either compound, suggesting that pectenotoxins do not belong in the diarrhetic shellfish poison group.
Miles
Christopher O
CO
AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand. chris.miles@agresearch.co.nz
Wilkins
Alistair L
AL
Munday
Rex
R
Dines
Mark H
MH
Hawkes
Allan D
AD
Briggs
Lyn R
LR
Sandvik
Morten
M
Jensen
Dwayne J
DJ
Cooney
Janine M
JM
Holland
Patrick T
PT
Quilliam
Michael A
MA
MacKenzie
A Lincoln
AL
Beuzenberg
Veronica
V
Towers
Neale R
NR
D000284:Administration, Oral; D000818:Animals; D004141:Dinoflagellida; D005260:Female; D005663:Furans / Q000008:administration & dosage / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D006868:Hydrolysis; D007274:Injections, Intraperitoneal; D007928:Lethal Dose 50; D018942:Macrolides; D008387:Marine Toxins / Q000008:administration & dosage / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity*; D051379:Mice; D011714:Pyrans / Q000008:administration & dosage / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D000095702:Polyether Toxins
D005663:Furans; D018942:Macrolides; D008387:Marine Toxins; D011714:Pyrans; C420916:pectenotoxin-2-seco acid; D000095702:Polyether Toxins; C098380:pectenotoxin 2