SUBERITENONE-A AND SUBERITENONE-B - SESTERTERPENOIDS OF AN UNPRECEDENTED SKELETAL CLASS FROM THE ANTARCTIC SPONGE SUBERITES SP

Suberitenones A (1) and B (2), sesterterpenoids of an unprecedented skeletal class, have been isolated from the Antarctic sponge Suberites sp. Structures of these compounds have been determined by combined spectral and chemical studies. Absolute stereochemistry has been assigned on the basis of a combination of the Kusumi and Kakisawa modification of Mosher's method and CD measurement, Suberitenone B inhibited the cholesteryl ester transfer protein (CETP), which mediates the transfer of cholesteryl ester and triglyceride between high-density lipoproteins and low-density lipoproteins, In addition, suberitenone A has been chemically transformed to suberiquinol (10), a hydroquinone derivative.