title: Instability and variable toxicity of HBP-Tx, a toxin in the cyanobacterium Microcystis aeruginosa.
abstract: It was found that autoxidative degradation is responsible for the inactivation of the unstable Microcystis toxin HBP-Tx. The purified toxin was similar in its properties to the "fast-death-factor" in Microcystis, described as a cyclic peptide in the literature. The apparent presence of an entirely different toxin was simulated by the partially inactivated HBP-Tx. A number of associated fluorescent compounds were identified as the non-toxic degradation products of the toxin. As a consequence, as established method for the detection of other algal toxins was applied. This chemical assay, which uses fluorescent measurement of the oxidized toxin in the cyanobacterium Aphanizomenon flos-aquae, was applicable for HBP-Tx after the removal of interfering degradation products of the toxin. The results obtained with Microcystis toxin HBP-Tx do not confirm suggestions concerning the structure of the "fast-death-factor".
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer / Q000379:methods; D004355:Drug Stability; D008387:Marine Toxins / Q000633:toxicity*; D051379:Mice; D046931:Microcystis / Q000502:physiology*; D010084:Oxidation-Reduction
chemical_list: D008387:Marine Toxins