Ionspray mass spectrometry of ciguatoxin-1, maitotoxin-2 and -3, and related marine polyether toxins.
A range of marine polyether toxins from dinoflagellates were analysed by ionspray mass spectrometry. Ciguatoxin-1 ([M+H]+ m/z = 1,111.8) purified from several fish species yielded singly charged ions corresponding to the parent ion, sodium and H2O adducts and ions for the loss of up to five H2O molecules. Ciguatoxin-1 was detected to 1 ng; however, interference from fish lipids precluded direct detection of ciguatoxin-1 in crude extracts from fish flesh spiked with ciguatoxin-1 at a level equivalent to 1.5 ng ciguatoxin-1/g of extracted flesh. Maitotoxin-2 yielded doubly and triply charged ions for sodium and potassium salts and likely possessed only one sulphate ester (M(r) = 3,298 for the mono-sodium salt). Maitotoxin-3, a recently isolated small maitotoxin, yielded singly charged ions including ions for the loss of one sulphate and up to four H2O molecules. Maitotoxin-3 is proposed to be a polyether compound possessing two sulphate esters (M(r) = 1,060.5 for the disodium salt). Brevetoxin-A ([M+H]+ m/z = 867.5) and brevetoxin-B ([M+H]+ m/z = 895.5) yielded singly charged ions corresponding to the parent ion, Na+ adducts and the loss of up to four H2O molecules. Okadaic acid ([M+H]+ m/z = 805.5) yielded singly charged ions corresponding to the parent ion and ions for the loss of up to three H2O molecules. A signal for M + 18 Da species that may represent [M+NH4]+ was observed for ciguatoxin-1, brevetoxin-A and -B, and okadaic acid. For all polyethers examined, the orifice potential influenced the relative intensity of the ions detected in a predictable manner.(ABSTRACT TRUNCATED AT 250 WORDS)
Lewis
R J
RJ
Southern Fisheries Centre, Queensland Department of Primary Industries, Australia.
Holmes
M J
MJ
Alewood
P F
PF
Jones
A
A
D000818:Animals; D002273:Carcinogens / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D002922:Ciguatoxins / Q000737:chemistry / Q000302:isolation & purification*; D004141:Dinoflagellida / Q000737:chemistry; D004524:Eels; D004988:Ethers, Cyclic / Q000737:chemistry / Q000302:isolation & purification; D005399:Fishes; D008387:Marine Toxins / Q000737:chemistry / Q000302:isolation & purification*; D013058:Mass Spectrometry / Q000379:methods; D019319:Okadaic Acid; D035964:Oxocins; D016339:Spectrometry, Mass, Fast Atom Bombardment; D000095702:Polyether Toxins
D002273:Carcinogens; D002922:Ciguatoxins; D004988:Ethers, Cyclic; D008387:Marine Toxins; D019319:Okadaic Acid; D035964:Oxocins; C043466:brevetoxin B; D000095702:Polyether Toxins; C053342:brevetoxin; C020394:maitotoxin