Quantitative analysis of azaspiracids in Azadinium spinosum cultures

Azadinium poporum from the Argentine Continental Shelf, Southwestern Atlantic, produces azaspiracid-2 and azaspiracid-2 phosphate

“…The third AZA compound detected in the Argentinean strains is AZA-2 methyl ester, most likely an extraction artifact caused by the use of methanol as solvent (Jauffrais et al, 2012). It has been observed before that extraction and storage of AZA containing samples results in methylation of the carboxylic acid function of AZA (Jauffrais et al, 2012;Krock et al, 2012). The fact that AZA-2 methyl ester is only present as a minor component is consistent with this interpretation.…”

“…9) and thus most likely underestimates the actual proportion of the phosphate of the AZA profile. The third AZA compound detected in the Argentinean strains is AZA-2 methyl ester, most likely an extraction artifact caused by the use of methanol as solvent (Jauffrais et al, 2012). It has been observed before that extraction and storage of AZA containing samples results in methylation of the carboxylic acid function of AZA (Jauffrais et al, 2012;Krock et al, 2012).…”

Mediterranean Azadinium dexteroporum (Dinophyceae) produces six novel azaspiracids and azaspiracid-35: a structural study by a multi-platform mass spectrometry approach

“…Water was deionized and purified through a MilliQ water purification system (Milli-Q, Millipore, Eschborn, Germany) to 18 AZA-1) and used for setting LC-HRMS n conditions and for quantitative analysis. A mussel tissue extract containing AZA-1, AZA-2, and AZA-3, kindly provided by Dr Philipp Hess (Ifremer, Nantes, France), and reference samples of AZA-7 and AZA-35, kindly provided by Dr Jane Kilkoyne (Marine Institute, Galway, Ireland), were used for toxins identification.…”

“…Considering that extraction with aqueous methanol may lead to formation of AZAs artifacts, including methyl esters and/or methyl ketals [18], another batch of A. dexteroporum was extracted using the procedure described by Jauffrais et al [18]. In particular, the pellet (1.4 × 10 5 cells) was suspended in 1 mL acetone/H 2 O (9:1, v/v), vortexed for 1 min, sonicated for 10 min, and centrifuged at 1000×g for 5 min.…”

“…Some AZAs (AZA-1 and AZA-2, among others) are actually produced by the dinoflagellates, whereas others (e.g., AZA-3 to AZA-19) seem to derive from biotransformation occurring in shellfish [9]. The formation of extraction artifacts (21-epi-AZA-1, AZA-29, AZA-30, and AZA-32) has also been demonstrated [18], especially when methanol is used as extraction solvent. Consequently, the extraction solvent currently suggested for AZA analysis is acetone or aqueous acetonitrile.…”