PSP toxins from Aphanizomenon flos-aquae (cyanobacteria) collected in the Crestuma-Lever reservoir (Douro river, northern Portugal)

The presence of paralytic shellfish poisoning (PSP) toxins in cultures of A phanizomenon flos-aquae, isolated from the Crestuma-Lever reservoir, was fo und by reversed phase high performance liquid chromatography employing two isocratic elution systems for the separation of PSP toxins. With the first isocratic elution protocol, the presence of apolar toxins as saxitoxin, dec arbamoyl saxitoxin and neosaxitoxin not detected. On the other hand, GTX4, GTX1 and GTX3 as well as Cs toxins were present either in the Aphanizomenon flos-aquae cells collected directly from the bloom or in the other toxic i solates priorly cultivated in laboratory conditions. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.