40 海綿Theonella sp.の抗腫瘍性マクロジオライドの構造(口頭発表の部)

抄録

During the course of our search for bioactive metabolites from Japanese marine invertebrates, we found that methanol extract of a sponge Theonella sp. collected in Hachijo-jima island revealed strong activity both in the echinoderm egg assay and in the cytotoxicity test. Fran this sponge we have isolated two active components, named bistheonellides A and B (1 and 2, respectively), which inhibited development of starfish embryos at 0.1 and 0.2μg/ml, respectively as well as growth of tumor cells at low concentrations. Bistheonellide A exhibited spectral data, except for molecular weight, identical with those for misakinolide A which had been reported from an Okinawan Theonella sponge. Direct comparison showed that both compounds were identical. On the basis of FABMS, molecular weight determination by vapor pressure method, and NMR analyses of octaacetyl and p-bromobenzoyl derivatives, bistheonellide A (misakinolide A) was revised from the previously proposed monomeric macrolide (3) to its dimeric macrodiolide (1). This was also confirmed by chemical degradation work. Similarly, bistheonellide B was found to have structure 2 by spectral and chemical analyses.