Taurospongin A, a Novel Acetylenic Fatty Acid Derivative Inhibiting DNA Polymerase β and HIV Reverse Transcriptase from Sponge <i>Hippospongia</i> sp.

Taurospongin A (<b>1</b>), a novel acetylene-containing natural product consisting of a taurine and two fatty acid residues, has been isolated from the Okinawan marine sponge <i>Hippospongia</i> sp. and its structure elucidated by spectral data and chemical means. Taurospongin A (<b>1</b>) exhibited potent inhibitory activity against DNA polymerase β and HIV reverse transcriptase. The absolute configurations of taurospongin A (<b>1</b>) were established to be 3<i>R</i>, 7<i>S</i>, and 9<i>R</i> by synthesis of the MTPA ester of a degradation product of <b>1</b>.