Many toxic secondary metabolites used for defense are also toxic to the producing organism. One important way to circumvent toxicity is to store the toxin as an inactive precursor. Several sulfated diesters of the diarrhetic shellfish poisoning (DSP) toxin okadaic acid have been reported from cultures of various dinoflagellate species belonging to the genus Prorocentrum. It has been proposed that these sulfated diesters are a means of toxin storage within the dinoflagellate cell, and that a putative enzyme mediated two-step hydrolysis of sulfated diesters such as DTX-4 and DTX-5 initially leads to the formation of diol esters and ultimately to the release of free okadaic acid. However, only one diol ester and no sulfated diesters of DTX-1, a closely related DSP toxin, have been isolated leading some to speculate that this toxin is not stored as a sulfated diester and is processed by some other means. DSP components in organic extracts of two large scale Prorocentrum lima laboratory cultures have been investigated. In addition to the usual suite of okadaic acid esters, as well as the free acids okadaic acid and DTX-1, a group of corresponding diol- and sulfated diesters of both okadaic acid and DTX-1 have now been isolated and structurally characterized, confirming that both okadaic acid and DTX-1 are initially formed in the dinoflagellate cell as the non-toxic sulfated diesters.

用于防御的许多有毒次生代谢产物也对产生生物具有毒性。规避毒性的一种重要方法是将毒素存储为无活性的前体。腹泻性贝类中毒（DSP）毒素冈田酸的数种硫酸二酯已从原副球藻属的各种鞭毛鞭毛藻物种的培养物中报告。。有人提出，这些硫酸二酯是毒素在鞭毛藻细胞中的一种储存方式，并且推定的酶介导的硫酸二酯如DTX-4和DTX-5的两步水解最初会导致二醇酯和最终释放出游离的冈田酸。然而，仅分离出一种二醇酯，没有分离出DTX-1（一种密切相关的DSP毒素）的硫酸二酯，这使一些人推测该毒素不是作为硫酸二酯储存的，而是通过其他方式加工的。两种大型原肠利马有机提取物中的DSP成分实验室文化已被调查。除了通常的冈田酸酯，游离酸冈田酸和DTX-1外，现在还对冈田酸和DTX-1的一组相应的二醇和硫酸二酯进行了分离和结构表征，这证实了冈田酸和DTX-1最初都是在鞭毛藻细胞中以无毒的硫酸二酯形式形成的。