Identification of 24-O-β-d-Glycosides and 7-Deoxy-Analogues of Okadaic Acid and Dinophysistoxin-1 and -2 in Extracts from Dinophysis Blooms, Dinophysis and Prorocentrum Cultures, and Shellfish in Europe, North America and Australasia

Chemistry and bioactivity of marine algal toxins and their geographic distribution in China

Marine algal toxins are usually produced by some toxic algae during toxic algal blooms which can be accumulated in marine organisms through food chains, leading to contamination of aquatic products. Consumption of the contaminated seafood often results in poisoning in human being. Although algal toxins are harmful for human health, their unique structures and broad spectrum of biological activities have attracted widespread attention of chemists and pharmacologists. Marine algal toxins are not only a reservoir of biological active compound discovery, but also powerful tools for exploring life science. This review first provides a comprehensive overview of the chemistry and biological activities of marine algal toxins, with the aim of providing references for biological active compound discovery. Additionally, typical shellfish poisoning incidents occurred in China in the past 15 years and the geographical distribution of the marine algal toxins in China Sea are discussed, for the purpose of enhancing public awareness of the possible dangers of algal toxins.

Seasonal occurrence of toxic phytoplankton and phycotoxins at a mussel aquaculture site in Nova Scotia, Canada

A three-year field study at a mussel (Mytilus edulis) aquaculture site in Ship Harbour, Nova Scotia, Canada was carried out between 2004 and 2006 to detect toxic phytoplankton species and dissolved lipophilic phycotoxins and domoic acid. A combination of plankton monitoring and solid phase adsorption toxin tracking (SPATT) techniques were used. Net tow and pipe phytoplankton samples were taken weekly to determine the abundance of potentially toxic species and SPATT samplers were deployed weekly for phycotoxin analysis. Mussels were also collected for toxin analysis in 2005. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyse the samples for spirolides (SPXs), pectenotoxins (PTXs), okadaic acid group toxins (OA, DTXs) and domoic acid (DA). Phycotoxins were detected with SPATT samplers beginning from the time of deployment until after the producing organisms were no longer observed in pipe samples. Seasonal changes in toxin composition occurred over the sampling period and were related to changes in cell concentrations of Alexandrium Halim, Dinophysis Ehrenberg and Pseudo-nitzschia (Hasle) Hasle. Spirolides peaked in late spring and early summer, followed by DA in mid-July. Okadaic acid, DTX1 and PTXs occurred throughout the field season but peaked in late summer. Concentrations of some phycotoxins detected in SPATT samplers deployed within the area where mussels were suspended on lines were lower than in those deployed outside the mussel farm. The SPATT samplers provided a useful tool to detect the presence of phycotoxins and to establish trends in their appearance in the Ship Harbour estuary.

A survey of Dinophysis spp. and their potential to cause diarrhetic shellfish poisoning in coastal waters of the United States

Multiple species of the genus Dinophysis produce diarrhetic shellfish toxins (okadaic acid and Dinophysis toxins, OA/DTXs analogs) and/or pectenotoxins (PTXs). Only since 2008 have DSP events (illnesses and/or shellfish harvesting closures) become recognized as a threat to human health in the United States. This study characterized 20 strains representing five species of Dinophysis spp. isolated from three US coastal regions that have experienced DSP events: the Northeast/Mid-Atlantic, the Gulf of Mexico, and the Pacific Northwest. Using a combination of morphometric and DNA-based evidence, seven Northeast/Mid-Atlantic isolates and four Pacific Northwest isolates were classified as D. acuminata, a total of four isolates from two coasts were classified as D. norvegica, two isolates from the Pacific Northwest coast were identified as D. fortii, and three isolates from the Gulf of Mexico were identified as D. ovum and D. caudata. Toxin profiles of D. acuminata and D. norvegica varied by their geographical origin within the United States. Cross-regional comparison of toxin profiles was not possible with the other three species; however, within each region, distinct species-conserved profiles for isolates of D. fortii, D. ovum, and D. caudata were observed. Historical and recent data from various State and Tribal monitoring programs were compiled and compared, including maximum recorded cell abundances of Dinophysis spp., maximum concentrations of OA/DTXs recorded in commercial shellfish species, and durations of harvesting closures, to provide perspective regarding potential for DSP impacts to regional public health and shellfish industry.

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1425 in 416 papers for 2021), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.