Aqueous photodegradation of okadaic acid and dinophysistoxin-1: Persistence, kinetics, photoproducts, pathways, and toxicity evaluation.

摘要: Abstract Diarrhetic shellfish poisoning (DSP) toxins are a class of natural organic contaminants that pose serious threat not only to marine ecosystems and fisheries but also human health. They widely distributed in coastal offshore waters around the world. However, persistence photochemical degradation characteristics DSP an aqueous environment still unclear. This study aimed elucidate fate two representative toxins, namely, okadaic acid (OA) dinophysistoxin-1 (DTX1). Results showed photo-mediated chemical reactions play crucial role eliminating seawater. OA DTX1 was relatively slow under solar radiation, with removal efficiency 90.0% after exposure for more than 20 days. When reaction solutions were exposed Hg lamp their followed pseudo-first-order kinetics, remarkably influenced by seawater pH metal-ion concentration. A total 24 tentative transformation products (TPs) identified via liquid chromatography high-resolution mass spectrometry. C12 (C43H66O11) C24 (C44H68O11) main TPs. The following possible photodegradation pathways proposed: decarboxylation, photoinduced hydrolysis, chain scission, photo-oxidation. Toxicity assays protein phosphatase 2A inhibition proved processes could significantly reduce toxicity irradiated approximately 88%. work provides enhanced understanding environment, allowing improved assessment environmental impacts.