Improved Isolation Procedure for Azaspiracids from Shellfish, Structural Elucidation of Azaspiracid-6, and Stability Studies

Improved isolation procedure for azaspiracids from shellfish, structural elucidation of azaspiracid-6, and stability studies.

Azaspiracids are a group of lipophilic polyether toxins produced by the small dinoflagellate Azadinium spinosum. They may accumulate in shellfish and can result in illnesses when consumed by humans. Research into analytical methods, chemistry, metabolism, and toxicology of azaspiracids has been severely constrained by the scarcity of high-purity azaspiracids. Consequently, since their discovery...

ISOLATION AND STRUCTURAL ELUCIDATION OF THE FIRST KNOWN C-HOMOPROTOBERBERINE

A novel C-homoprotoberberine alkaloid, Hediamine (2), has been isolated from the roots of Berberis actinucantha (Berberidaceae). Conclusive proof for the structure of hediamine was obtained by its comparison with the isomeric lactam (4), by chemical transformation, and by means of spectroscopic techniques (UV, IR, MS, NMR).

Isolation, purification, and structural elucidation of polysaccharides from Alhagi-honey.

The polysaccharide extract (PE) of Uyghur medicinal preparation Alhagi-honey was prepared by water extraction and alcohol precipitation method. The purified polysaccharide AP1-1 was obtained from PE by macroporous adsorption resin chromatography, DEAE cellulose chromatography, and Sephadex gel chromatography; the homogeneity and the molecular weight of AP1-1 were determined by gel filtration; a...

Isolation, structure elucidation, relative LC-MS response, and in vitro toxicity of azaspiracids from the dinoflagellate Azadinium spinosum.

We identified three new azaspiracids (AZAs) with molecular weights of 715, 815, and 829 (AZA33 (3), AZA34 (4), and AZA35, respectively) in mussels, seawater, and Azadinium spinosum culture. Approximately 700 μg of 3 and 250 μg of 4 were isolated from a bulk culture of A. spinosum, and their structures determined by MS and NMR spectroscopy. These compounds differ significantly at the carboxyl en...

isolation and structural elucidation of natural products in euphorbia erythradenia