Biosynthetic studies of the DSP toxin skeleton

Abstract

Marine toxins have drawn wide interest because their economical impact and disastrous effect upon the shellfish industry and public health in many parts of the world. One of the most interesting group of substances of marine toxins, from structural and pharmacological points of view are polyether compounds, which generally present a great diversity in size and potent biological activities. The subject of this work was about to biosynthesis of okadaic acid skeleton as leader as DSP toxins. Its biosynthesis attracts considerable attention since the carbon skeleton has been shown to be synthesised via an unusual route. In this paper we report on stable isotope incorporation experiments on DSP toxin in artificial cultures of dinoflagellate. The comparison of the degrees of incorporation in these samples measured by different methods led to contradictory results. This implies that further experimental data is needed in order to propose a logical biogenetic scheme.

The Mechanism of Diarrhetic Shellfish Poisoning Toxin Production in Prorocentrum spp.: Physiological and Molecular Perspectives

“…Several precursor incorporation studies have also indicated that the PKS pathway participates in DSP toxin biosynthesis [137,138,139,140,141]. Glycolate from photorespiration is a deemed precursor of OA synthesis and side chains of DTX-5 (side chain c and d of R 5 in Figure 1).…”

Chemical Defenses: From Compounds to Communities

“…Unfortunately, radiolabeled feeding studies have proven to be quite difficult since Prorocentrum and Dinophysis are very selective genera that undergo autotrophic and heterotrophic metabolism (Izumikawa et al, 2000;Daranas et al, 2004). Daranas and colleagues suggested (2004) that the carbon skeleton of OA is synthesized by an unusual route regarding the direct condensation reactions (acetate, proprionate, or butyrate units) associated with polyethers of terrestrial origin.…”

“…Daranas and colleagues suggested (2004) that the carbon skeleton of OA is synthesized by an unusual route regarding the direct condensation reactions (acetate, proprionate, or butyrate units) associated with polyethers of terrestrial origin. Those authors believed that the parent compound is assembled from a polyketide chain, with glycolate as a starter unit and subsequent additions of acetate (Daranas et al, 2004). The involvement of the tricarboxylic acid cycle in incorporating polyketide fragments into a polyether backbone is unusual and is characteristic of the biosynthesis of dinoflagellate toxins (Shimizu, 1993).…”

Critical Contribution of Aromatic Rings to Specific Recognition of Polyether Rings

“…Among these, the antibody-based immunoassay is attractive, because it is accurate, sensitive, easily performed, and portable. During the development of this immunoassay, extensive studies focused on preparing antibodies with high specificity for ciguatoxin, and recently a sandwich enzymelinked immunosorbent assay using high affinity antibodies specific to both ends of CTX3C was established that can detect CTX3C down to the parts per billion level without cross-reactivity against other related marine toxins (14,15), including brevetoxin A (17), brevetoxin B (18), okadaic acid (19), and maitotoxin (5).…”

“…Moreover, many marine toxins have polyether structures. These toxins include maitotoxin (5) and gambierol, which also cause ciguatera (5), brevetoxin, which causes neurotoxic shellfish poisoning (17,18), dinophysistoxins, which cause diarrheic shellfish poisoning (19), palytoxin (20), and yessotoxin (21). Therefore, research focused on antibodies that can recognize polyether compounds may produce a more effective antibody-based immunoassay based on well understood mechanisms.…”