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Abstract: The accumulation of saxitoxins (STXs) in fish from freshwater aquaculture was investigated for the first time in the present study. Cyanotoxins have been monitored in liver and muscle samples of Oreochromis niloticus by chromatographic methods, both before and after the depuration process. The results show that tilapia can accumulate STXs. Our findings suggest that depuration with clean water is an alternative process to eliminate STXs from fish and, therefore, improve the safety of tilapia for consumers. [Copyright &y& Elsevier]

Abstract: Cyanobacteria produce a wide range of potent toxins, including hepatotoxic microcystins. HPLC methods for microcystin analysis and purification almost invariably include acetonitrile in the elution gradient mobile phase. The recent, acute, global acetonitrile shortage requires that adequate methods are available for microcystin analysis and purification without the need for acetonitrile. Here we present a convenient methanol-based method for effective HPLC analysis and purification of the toxins, with full separation of a range of microcystin variants. [Copyright &y& Elsevier]

Abstract: Venom components from the centipede Scolopendra viridis Say were studied, using both the soluble venom and a cDNA library prepared from mRNA of the venomous glands. Separation of the soluble venom by high performance liquid chromatography (HPLC) permitted to obtain at least 54 different fractions. The fraction eluting at 46.24min showed phospholipase activity. The enzyme was purified to homogeneity and the first 25 amino acid residues were identified by Edman degradation. From the cDNA library several genes were cloned, one of which codes for a protein with identical amino acid sequence as the one experimentally determined. The cloned gene codes for a signal peptide of 28 amino acids and a mature peptide of 119 residues. The molecular weight of the enzyme was estimated by mass spectrometry and shown to be 13,752Da, which matches exactly with the molecular mass expected from the deduced amino acid sequence of the gene. Phylogenetic analysis of this sequence, in comparison with other known from venomous animals, showed that it is more similar to snake phospholipases than to insect or arachnid sequences, suggesting that it has been submitted to convergent evolution. To the best of our knowledge this is the first time that a phospholipase from this species of animal is fully characterized. We have named it Scol/Pla. [Copyright &y& Elsevier]