Use of circular dichroism for assigning stereochemistry of sphingosine and other long-chain bases

Bioactive lipids from the sponge Spirastrella abata

Three sphingosine 4-sulfates (1-3) and a lysophosphatidylglycerol (4) were isolated from the Korean sponge Spirastrella abata. The structures of these compounds were determined based on the combined results of spectroscopic analyses. Based on the results of combined synthesis and comparison of specific rotation and circular dichroism, the absolute configurations of 1-3 were found to be enantiomeric to the previously isolated metabolites. The configurations of 4 were also partially determined by similar chemical and spectroscopic methods. The compounds exhibited significant cytotoxicity and weak antimicrobial activity (1), as well as weak-to-moderate inhibitory activity against isocitrate lyase and Na(+)/K(+)-ATPase. A structure-activity relationship was found for the sphingosine 4-sulfates.