ARAGUSTEROLS-E-H, NEW 26,27-CYCLOSTEROLS FROM THE OKINAWAN MARINE SPONGE OF THE GENUS XESTOSPONGIA AND ABSOLUTE-CONFIGURATIONS OF XESTOKEROL-A AND XESTOKEROL-AB
H. Miyaoka et al., ARAGUSTEROLS-E-H, NEW 26,27-CYCLOSTEROLS FROM THE OKINAWAN MARINE SPONGE OF THE GENUS XESTOSPONGIA AND ABSOLUTE-CONFIGURATIONS OF XESTOKEROL-A AND XESTOKEROL-AB, Tetrahedron, 53(15), 1997, pp. 5403-5412
New 20, 27-cyclosterols, aragusterols E-H, were isolated from the Okin
awan marine sponge of the genus Xestospongia. Their structures were de
termined by spectroscopic measurement and chemical conversion. The abs
olute configurations of xestokerols A and B were determined by chemica
l conversion. (C) 1997 Elsevier Science Ltd.