TY - JOUR
T1 - The presence of 12β-deoxydecarbamoylsaxitoxin in the Japanese toxic dinoflagellate Alexandrium determined by simultaneous analysis for paralytic shellfish toxins using HILIC-LC-MS/MS
AU - Cho, Yuko
AU - Tsuchiya, Shigeki
AU - Yoshioka, Renpei
AU - Omura, Takuo
AU - Konoki, Keiichi
AU - Oshima, Yasukatsu
AU - Yotsu-Yamashita, Mari
N1 - Funding Information:
This work was supported by grants from the Funding Program for Next-Generation World-Leading Researchers ( LS012 ) to M.Y.Y. and by KAKENHI Grants-in-Aid for Scientific Research to M.Y.Y. (no. 26292057 ) and Y.C. (no. 24580295 and 15K07569 ). S.T. was the recipient of a SUNBOR scholarship from the Suntory Institute for Bioorganic Research and S.T. is a research fellow of Japan Society for the Promotion of Science (DC2) (no. 15J00480) JSPS (DC2) (no. 15J00480). We thank Dr. T. Ishimaru of Tokyo University of Marine Science and Technology, who kindly donated the A. tamarense clonal culture strains Axat-2 and UAT-014-009, and we thank Dr. K. Koike of Hiroshima University for the A. catenella clonal culture strains 120518KureAC and 0807KureAC.[SS]
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/11
Y1 - 2015/11
N2 - A differential screening study using high-resolution (HR)-hydrophilic interaction chromatography (HILIC)-electrospray ionization (ESI)-quadrupole time-of-flight mass spectrometry (Q-TOF MS) was conducted to identify saxitoxin (STX) analogues in the marine dinoflagellate toxic sub-clone Alexandrium tamarense Axat-2 and the non-toxic sub-clone UAT-014-009 derived from the same Japanese isolate. One unknown compound was identified only in the toxic sub-clone and was found to have the molecular formula C9H16N6O2. This structure differed from that of decarbamoyl STX (dcSTX; C9H16N6O3) by the loss of a single oxygen. A 12-deoxy-dcSTX standard (a mixture of 12α- and β-deoxy-dcSTX) was chemically prepared from dcSTX by reduction with sodium borohydride. The unknown compound in the toxic strain of A. tamarense was identified as 12β-deoxy-dcSTX by comparison of its HR-HILIC-LC-MS retention time and HR-MS/MS spectrum with those of the chemically prepared standard, and the identification was confirmed by high-sensitivity HPLC analysis with post-column fluorescent derivatization. Moreover, two Japanese isolates of A. catenella showing toxin profiles different from that of A. tamarense were also found to contain 12β-deoxy-dcSTX. Previously, 12β-deoxy-dcSTX was isolated from the freshwater cyanobacterium Lyngbya wollei, which produces a unique set of STX analogues. This study is the first evidence of the presence of 12β-deoxy-dcSTX in marine dinoflagellates.
AB - A differential screening study using high-resolution (HR)-hydrophilic interaction chromatography (HILIC)-electrospray ionization (ESI)-quadrupole time-of-flight mass spectrometry (Q-TOF MS) was conducted to identify saxitoxin (STX) analogues in the marine dinoflagellate toxic sub-clone Alexandrium tamarense Axat-2 and the non-toxic sub-clone UAT-014-009 derived from the same Japanese isolate. One unknown compound was identified only in the toxic sub-clone and was found to have the molecular formula C9H16N6O2. This structure differed from that of decarbamoyl STX (dcSTX; C9H16N6O3) by the loss of a single oxygen. A 12-deoxy-dcSTX standard (a mixture of 12α- and β-deoxy-dcSTX) was chemically prepared from dcSTX by reduction with sodium borohydride. The unknown compound in the toxic strain of A. tamarense was identified as 12β-deoxy-dcSTX by comparison of its HR-HILIC-LC-MS retention time and HR-MS/MS spectrum with those of the chemically prepared standard, and the identification was confirmed by high-sensitivity HPLC analysis with post-column fluorescent derivatization. Moreover, two Japanese isolates of A. catenella showing toxin profiles different from that of A. tamarense were also found to contain 12β-deoxy-dcSTX. Previously, 12β-deoxy-dcSTX was isolated from the freshwater cyanobacterium Lyngbya wollei, which produces a unique set of STX analogues. This study is the first evidence of the presence of 12β-deoxy-dcSTX in marine dinoflagellates.
KW - 12β-Deoxydecarbamoylsaxitoxin
KW - Alexandrium catenella
KW - Alexandrium tamarense
KW - Dinoflagellate
KW - LC-MS/MS
KW - Paralytic shellfish toxins
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U2 - 10.1016/j.hal.2015.09.003
DO - 10.1016/j.hal.2015.09.003
M3 - Article
AN - SCOPUS:84947431668
SN - 1568-9883
VL - 49
SP - 58
EP - 67
JO - Harmful Algae
JF - Harmful Algae
ER -
