Detection of Dinophysistoxin-1 in Clonal Culture of Marine Dinoflagellate Prorocentrum foraminosum (Faust M.A., 1993) from the Sea of Japan

Abstract

For the first time the presence of dinophysistoxin-1 (DTX-1) in a culture of Prorocentrum foraminosum was revealed in cells and in the culture medium. The clone was isolated from coastal waters of the Sea of Japan and identified by molecular analyses of SSU and D1/D2 regions of LSU rDNA. The concentration of DTX-1 in cells was 8.4 ± 2.5 pg/cell and, in cell-free media, 27.9 ± 14.7 µg/L. The toxin presence was confirmed by HPLC with high-resolution tandem mass-spectrometry.

Keywords: DTX-1; HPLC-HRMS; Prorocentrum foraminosum; Russia; molecular identification.

Figure 1

Consensus maximum-likelihood tree based on nuclear SSU rDNA sequences of several members of Prorocentrum. Posterior probability, maximum-likelihood, and neighbor-joining bootstrap values <0.5/50/50 are shown from left to right (BI/ML/NJ). Scale bar represents the number of nucleotide substitutions/site.

Figure 2

Consensus maximum-likelihood tree based on nuclear D1/D2 region of LSU rDNA sequences of several members of Prorocentrum. Posterior probability, maximum-likelihood, and neighbor-joining bootstrap values <0.5/50/50 are shown from left to right (BI/ML/NJ). Scale bar represents number of nucleotide substitutions/site.

Figure 3

Chromatograms obtained by the HPLC-FLD analyses of the derivatized by 4-BrM-7-MC samples. (A) standard solution of OA (17 µM; 50 µL), DTX-1 (18.5 µM; 50 µL), DTX-2 (9.5 µM; 50 µL), DCA (20.3 µM; 50 µL); (B) extract of P. foraminosum cells with DCA (5.075 µM; 25 µL); (C) extract of P. foraminosum cells free media with DCA (5.075 µM; 25 µL). Numbers: 1—OA, 2—DTX-2, 3—DTX-1, 4—DCA, 5—unknown compound.

Figure 4

APCI-MS of M-7-MC derivative of DCA.

Figure 5

(A) APCI-MS of unknown component (Figure 3B,C, peak 5); (B) MS² of parent ions with m/z 817.4778.