Calyculin from Discodermia calyx

The Japanese sponge Discodermia calyx has yielded the new calyculin, calyculin J (1669) (1631). The highly toxic (ichthyotoxicity, hemolytic activity) prymnesin-1 (1670) and -2 (1671), possessing unprecedented structural complexity, were characterized from the red tide alga Prymnesium parvum (1632-1634). 

Matsunaga S, Wakimoto T, Fusetani N (1997) Isolation of Four New Calyculins from the Marine Sponge Discodermia calyx. J Org Chem 62 2640... 

Calyculins A-H are bioactive metabolites isolated from the sponge Discodermia calyx Calyculins are potent serine-threonine protein phosphatase (PPl and PP2A) inhibitors and endowed with remarkable cell membrane permeability. The absolute stereochemistry of calyculins and its C33—C37 portion has been investigated. The relative configuration of the stereocenters was determined by X-ray analysis. ... 

The calyculins make up a family of potent, selective serine-threonine phosphatase inhibitors, which have been isolated from the Japanese sponge Discodermia calyx.There are at least 13 different members of this family, and the most abundant are calyculin A 1189a and calyculin C 1189c." As nanomolar inhibitors of protein phosphatases 1 and 2A (PPl and PP2A), 1189a and analogs have... 

Kato, Y, Fusetani, N., Matsunaga, S., Hashimoto, K., Fujita, S., and Furuya, T. (1986a) Calyculin A, a novel antitumor metabolite from the marine sponge Discodermia calyx. J. Am. Chem. Soc., 108, 2780-2781. 

Matsunaga, S., Fujiki, H., Sakata, D., and Fusetani, N. (1991b) Calyculins E, F, G, and H, additional inhibitors of protein phosphatases 1 and 2A, from the marine sponge Discodermia calyx. Tetrahedron, 47, 2999-3006. 

Matsunaga, S., Wakimoto, T, Fusetani, N and Suganuma, M. (1997a) Isolation of four new calyculins from the marine sponge Discodermia calyx. /. Org. Chem., 62, 2640-2642. Addition/correction J. Org. Chem., 62, 9388. 

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