Protoperidinium

Dinoflagellates Dinophysis spp., Prorocentrum lima Diatoms Pseudo-nitzschia spp. Dinoflagellates Protoperidinium spp. Epibenthic dinoflagellates Gambierdiscus toxicus Possibly Ostreopsis spp. Coolia spp. or Prorocentrum spp. 

The azaspiracids are another class of polyether toxins with unique spiro ring assemblies, a cyclic amine and a carboxylic acid. Five analogs have been described (Ofuji et al., 1999, 2001 Satake et al., 1998). Azaspiracids are produced by species of the dinoflagellate Protoperidinium, a phytoplankton genus historically thought to be benign (James et al., 2003a). 

Figure 17.1. Protoperidinium crassipes. Average dimensions 0.1 x 0.12 mm. Reprinted from James et al. 2003, with permission from Elsevier.

Latz, M.I., and Jeong, H.J. 1996. Effect of red tide dinoflagellate diet and cannibalism on file bioluminescence of the heterotrophic dinoflagellates Protoperidinium spp. Mar EcolProg Ser 132, 275-285. 

Azaspiracids [azaspiracid-1 (18)] are another class of highly unusual polyketide polyethers originally isolated from Irish mussels that caused azaspiracid shellfish poisoning (5). They are produced by the dinoflagellate Protoperidinium crassipes. A similar class of polyether toxins named pinnatoxins [pinnatoxin A (19)] were reported from the bivalve Pinna pectinata a closely related species P. attenuata is known to cause food poisoning in China. Pinnatoxins are likely of dinoflagellate origin and activate Ca channels (15). 

Azaspiracids Not fully established. Possibly Protoperidinium crassipes... 

Like other Protoperidinium species, P. crassipes is a pallium-feeder, that is, extends a spider web-like structure or pseudopodium called a pallium to trap prey (other diatoms and dinoflagellates) digestion is extracellular [81], Successful cultures of P crassipes on L. polyedra have been described [82]. 

Several Dinophysis species are the main worldwide sources of OAs and PTXs. YTXs prodnced by L. polyedra, P. reticulatum, and G. spinifera are a more recently identified problem. Widespread application of LC-MS analyses will lead to identification of a mnch larger hst of cansative species. AZP toxins, so far associated with P. crassipes, seem to be a Enropean problem, bnt their presence has not been properly explored elsewhere. Bloom dynamics, toxin profiles, and toxin content per cell need to be stndied on regional and local scales. Some key issnes that reqnire farther research and/or improved procedures and tools are (a) genetic (inter- and intraspecific) variabihty of Dinophysis spp. (b) identification of inocnlnm popnlations and other behavioral processes (c) toxin production studies in cnltnres of Dinophysis and Protoperidinium spp. and (d) improved determination of hidden toxins, snch as diol esters of OA, in microalgal extracts. 

The discovery of the phytoplankton source of azaspiracids was achieved using LC-MS determination on monocultures (200 cells) of Protoperidinium spp., manually collected from mixed populations of phytoplankton (Figure 35.6). The toxin profile observed contained a somewhat... 

Structure, nomenclature and occurrence The group of marine toxins known as azaspiracids (AZA) was only recently discovered to be the cause of shellfish poisoning in humans. Their source is the algae of the genus Protoperidinium. Azaspiracids are a group of polyethers (such as okadaic acid), but they contain a nitrogen heterocyclic amine piperidine (10-246). About 20 different derivatives have... 

---