Corozalic acid: a key okadaic acid biosynthetic precursor with phosphatase inhibition activity.

Toxin precursors: Corozalic acid, a new Ser/Thr protein phosphatase 1 and 2A inhibitor that turned out to be a key metabolic intermediate, was isolated from cultures of the marine dinoflagellate Prorocentrum belizeanum. Detailed spectroscopic analysis and extensive computational calculations revealed its structure and conformational behavior. In addition, a comprehensive picture of the interactions of corozalic acid with PP1 and PP2A is proposed (see figure) on the basis of ab initio, docking and molecular dynamics calculations.