Yessotoxin analogues in several strains of Protoceratium reticulatum in Japan determined by liquid chromatography-hybrid triple quadrupole/linear ion trap mass spectrometry

Several strains of Protoceratium reticulatum, one of the dinoflagellates producing yessotoxins (YTXs), were collected from various shellfish producing areas in Japan. YTXs in the cultured strains were analyzed by liquid chromatography-mass spectrometry (LC-MS). Neutral loss scan monitoring, multiple reaction monitoring (MRM) for more than 20 YTX analogues, and full-scan MS/MS spectra obtained with a hybrid triple quadrupole/linear ion trap mass spectrometer showed that yessotoxin (YTX), 45,46,47-trinoryessotoxin (trinorYTX), 1-homoyessotoxin (homo YTX), and 45,46,47-trinor-1-homoyessotoxin (trinor-1-homo YTX) were the dominant toxins in these strains of P. reticulatum. Enone isomer of 42,43,44,45,46,47,55-heptanor-41-oxoyessotoxin (noroxo YTX enone) was also detected in some strains. Toxin profiles and contents were different among the strains. Some strains produced YTX, trinorYTX, 1-homo YTX, trinor-1-homo YTX, and noroxo YTX enone, whereas other strains produced only YTX or 1-homo YTX. This is the first identification of 1-homo YTX and noroxo YTX enone in P. reticulutum in Japan. Some strains did not produce any detectable YTX analogues. (c) 2006 Elsevier B.V. All rights reserved.