Occurrence of 12-methylgymnodimine in a spirolide-producing dinoflagellate Alexandrium peruvianum and the biogenetic implications

Identification of gymnodimine D and presence of gymnodimine variants in the dinoflagellate Alexandrium ostenfeldii from the Baltic Sea

“…In addition, more connectivities were seen because of higher sample concentration. The observed 1 H and 13 C ppm values were similar to the values measured for the corresponding functional groups of gymnodimine A (2) (Seki et al, 1995) and 12-methylgymnodimine (5) (Van Wagoner et al, 2011). The comparison of the chemical shifts for 1, 2, and 5 is presented in the supporting information (Table S1).…”

“…The genetic basis for cyclic imine production is presently not very well understood. Previously it was found that A. ostenfeldii isolates from U.S East Coast estuaries and brackish coastal waters in the Netherlands produce both PSP toxins and cyclic imines, spirolides as well as various gymnodimines (Van Wagoner et al, 2011;Van de Waal et al, 2015). The respective isolates are phylogenetically closely related to A. ostenfeldii populations from the Baltic Sea , which motivated us to search for gymnodimines in Baltic A. ostenfeldii cultures.…”

“…These gymnodimines can be present in filter-feeding shellfish throughout the year, and have been detected in large quantities in coastal waters of New Zealand (Stirling, 2001) and Tunisia (Bire et al, 2002;Ben Naila et al, 2012) after prolonged blooms of K. selliformis. Recently, 12-methylgymnodimine (5) was isolated from A. ostenfeldii originating from estuaries at the U.S. East Coast, which was the first report of gymnodimines in Alexandrium or any other dinoflagellate species besides K. selliformis (Van Wagoner et al, 2011). Besides 12-methylgymnodimine isolated from an A. ostenfeldii strain from the U.S. East Coast, gymnodimine A and 12-methylgymnodimine have been found together with spirolides in isolates from a recent bloom of A. ostenfeldii in the Netherlands ( Van de Waal et al, 2015).…”

“…Several unknown analogues have also been described together with known spirolides (Sleno et al, 2004;Almandoz et al, 2014;Tillmann et al, 2014;Rundberget et al, 2011). Certain A. ostenfeldii isolates may produce both spirolides and gymnodimines (Van Wagoner et al, 2011;Van de Waal et al, 2015). Due to their structural similarity, a possible explanation may be a common biosynthetic pathway.…”

Toxigenic algae and associated phycotoxins in two coastal embayments in the Ebro Delta (NW Mediterranean)

“…Furthermore, there was no clear link between the distribution of likely toxigenic source organisms and the macrocyclic imine toxin SPX-1, elsewhere attributed to Alexandrium ostenfeldii (Cembella et al, 1999(Cembella et al, , 2000. This apparent lack of coherence between the presence of the toxin and the associated taxon also applied to GYM, usually produced by Karenia selliformis (Medhioub et al, 2009;Miles et al, 2003), or in brackish water by A. ostenfeldii (Harju et al, 2016;Van de Waal et al, 2015;Van Wagoner et al, 2011). High amounts of these toxins (Table 2) were detected in only one sample, and this simultaneous presence may indicate A. ostenfeldii as producer species of both toxins (Harju et al, 2016;Van de Waal et al, 2015;Van Wagoner et al, 2011).…”