Structure and Absolute Configuration of Karlotoxin-2 an Ichthyotoxin from the Marine Dinoflagellate Karlodinium veneficum

摘要

In an attempt to determine the cause of repeated fish kills in an estuarine aquaculture facility in Maryland, a toxin was isolated from Karlodinium veneficum with hemolytic, cytotoxic, and ichthyotoxic properties, which was referred to as karlotoxin-2 (KmTx2). The structure of KmTx2 was elucidated by means of detailed 1D and 2D NMR spectra including 2D INADEQUATE. The relative and absolute configuration of karlotoxin-2 was determined using J-based configuration analysis and comparison of degradation products with synthetic controls.