Hemolytic polar steroidal constituents of the starfish Aphelasterias japonica

A reinvestigation of the polar steroid fraction from the starfish Aphelaste rias japonica, collected near the Russian shore of the Sea of Japan, has af forded two new compounds, the disulfated quinovoside aphelasteroside C (1) and the monosulfated polyhydroxysteroid aphelaketotriol (2). Compounds 1 an d 2 contain a unique 23-oxo-24-hydroxylated side chain that is unprecedente d in marine steroids. The known compounds cheliferoside L1 (3), 3-O-sulfoas terone (4), forbeside E3 (5), and 3-O-sulfothornasterol A (6) were also iso lated from this source. Compounds 1-3, 5, and 6 showed hemolytic activity t o mouse erythrocytes.