Determinationof the Hepatotoxin Cylindrospermopsin Produced by

theCyanobacterium CylindrospermopsisRaciborskii

ReportNo WSAA 123

July 1997

SYNOPSIS

Thisproject was carried out with 3 aims:

·        To isolate sufficient cylindrospermopsin from bloom/cultured materialto use as a chemical standard in an analytical method

·        To develop a method for the determination of cylindrospermopsin incyanobacterial material and water

·        To carry out some preliminary investigations of the behaviour ofcylindrospermopsin in water treatment processes

ToxicCylindrospermopsis raciborskii wassuccessfully cultured. However attempts to isolate the pure toxin usingsemi-preparative HPLC by monitoring toxicity of collected fractions with themouse bioassay were unsuccessful. Once an analytical standard ofcylindrospermopsin was obtained, it was relatively easy to identify thefraction containing this toxin. Had time been available, the isolation ofsufficient material for use as an analytical standard and in investigations ofits behaviour during water treatment should have been possible usingsemi-preparative HPLC. Using cytotoxicity testing for determining the presenceof cylindrospermopsin was also unsuccessful.

Liquidchromatography/mass spectometry (LC/MS) employing direct interface of the HPLCinjector to the mass spectrometer and selective ion recording (SIR) was capableof determining the presence of cylindrospermopsin in cultures. The resultssuggested that this toxin should be able to be monitored by conventionalthermospray LC/MS.

Experimentsaimed at determining whether cylindrospermopsin was removed by processes usedfor water disinfection, eg, chlorine and UV radiation, were relativelyunsuccessful. There was some indication that treatment with chlorine removedsome toxin. Further water treatment studies should be carried out as a matterof urgency due to the recent blooms of toxic C. raciborskii in Australian reservoirs.

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