CALLYSPONGIN-A AND CALLYSPONGIN-B - NOVEL POLYACETYLENE SULFATES FROMTHE MARINE SPONGE CALLYSPONGIA-TRUNCATA THAT INHIBIT FERTILIZATION OFSTARFISH GAMETES

Bioassay-guided fractionation of the fertilization-inhibitory constitu ents of the marine sponge Callyspongia truncata yielded two novel poly acetylene sulfates designated callyspongins A (1) and B (2). The struc tures were determined an the basis of spectroscopic data. Compounds 1 and 2 inhibited fertilization of starfish gametes with minimum inhibit ory concentrations of 6.3 and 50 mu M, respectively, but affected neit her maturation of oocytes nor cell division of embryos. These findings indicate that the sulfate group plays an important role in specific i nhibition of starfish fertilization.