Aurantoside L, a New Tetramic Acid Glycoside with Anti-Leishmanial Activity Isolated from the Marine Sponge Siliquariaspongia japonica .

A new tetramic acid glycoside, aurantoside L ( 1 ), was isolated from the sponge Siliquariaspongia japonica collected at Tsushima Is., Nagasaki Prefecture, Japan. The structure of aurantoside L ( 1 ) composed of a tetramic acid bearing a chlorinated polyene system and a trisaccharide part was elucidated using spectral analysis. Aurantoside L ( 1 ) showed anti-parasitic activity against L. amazonensis with an IC 50 value of 0.74 µM.