pectenotoxin-2 and pectenotoxin-6

Conditions for the determination of lipophilic marine toxins, such as yessotoxins and pectenotoxins (PTX)-6, were investigated with capillary electrophoresis coupled to mass spectrometry (MS) with an electrospray ionization source. After optimization, a simple and MS compatible alkaline volatile buffer solution of ammonium acetate was selected as background electrolyte, with isopropanol/water (80/20, v/v) sheath liquid modified with ammonium acetate used at the electrospray ionization (ESI) source. Previously to capillary electrophoresis (CE) separations, the application of an on-line sample pre-concentration approach based on field-amplified sample stacking was accomplished to increase sensitivity. As a result, the limits of detection provided by capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) were 0.02 microg ml(-1) (0.01 microg g(-1)), which corresponded to 1.25 pg for yessotoxin and 0.25 microg ml(-1) (0.13 microg g(-1) and 13.25 pg on capillary) for PTX-6. Accuracy tests showed 97.7% recovery from spiked blank mussel samples that showed no significant matrix influence running under optimal conditions. Intermediate precision was close to 4% relative standard deviation (RSD) for the migration time, and an RSD of 7.5% for peak areas. The method was successfully applied to naturally contaminated seafood samples in which yessotoxins and pectenotoxins-6 were clearly determined. This work demonstrated the potential of CE-ESI-MS to be applied for a sensitive determination of lipophilic toxins from the marine environment as alternative to liquid chromatography-electrospray ionization-single quadrupole mass spectrometry (LC-ESI-MS) for this purpose.

Topics: Animals; Furans; Macrolides; Marine Toxins; Mollusk Venoms; Oxocins; Pyrans; Sensitivity and Specificity; Shellfish; Spain; Spectrometry, Mass, Electrospray Ionization

Diarrhetic activity of pectenotoxin-6 (PTX6), a shellfish contaminant in Japanese scallops (Patinopecten yessoensis), was studied in vivo. Mice gavaged with 5mg/kg PTX6 did not show diarrhea or fluid secretion, and no prominent pathological changes were observed. There was no synergistic toxicity of PTX6 with okadaic acid (OA) or pectenotoxin-2 (PTX2) when toxins were given to mice by gavage. Synergistic activity of PTX6 with OA was also not confirmed under crude conditional simulation with oil. In contrast to the oral administration to mice, PTX6 at 500 microg/kg by i.p. was the lethal dose with bleeding in the liver, injuries at the gastric organs and the kidney. When rats were gavaged with PTX6 at a dose of 2 mg/kg, PTX6 did not have diarrhetic activity; however, the middle-lower small intestine (jejunum-ileum) was eroded at villi by edema. PTX6 is a potent toxin if administered by intraperitoneal injection to mice, or if administered orally to the rat. However, it is not clear if PTX6 passes through the intestinal barrier if given by the oral route.

Topics: Animals; Diarrhea; Dose-Response Relationship, Drug; Furans; Intestine, Small; Macrolides; Male; Marine Toxins; Mice; Mice, Inbred ICR; Molecular Structure; Okadaic Acid; Pectinidae; Pyrans; Rats; Rats, Wistar; Time Factors

Solid-phase extraction of pectenotoxin-2 (PTX2) and pectenotoxin-6 (PTX6) from seawater samples using a nonpolar cartridge column Sep-Pak C18 was investigated for determination of PTXs in toxic phytoplankton. PTX2 and PTX6 were almost completely recovered from the seawater samples. Determinations of PTX2 from the toxic phytoplankton and scallops were carried out by liquid chromatography (LC) on UV trace equipped with an atmospheric pressure electrospray ionization mass spectrometry (ESI-MS). PTX2 obtained from the toxic phytoplankton and scallops yielded a mass spectra exhibiting abundant [M+H]+, [M+NH4]+ and [M+Na]+ indicating that ESI-MS is useful for the identification of PTX2. Determinations of PTX6 from the toxic phytoplankton and scallops were carried out by LC fluorescence detection. A significantly higher content of PTX6 compared to PTX2 in scallops was observed, suggesting that a transformation of PTX2 to PTX6 in tissues of the scallops occurs rapidly.

Topics: Animals; Chromatography, High Pressure Liquid; Dinoflagellida; Furans; Macrolides; Mass Spectrometry; Mollusca; Oxidation-Reduction; Pyrans; Seawater; Spectrophotometry, Ultraviolet