Aurantosides G, H, and I: Three New Tetramic Acid Glycosides from a Papua New Guinea Theonella swinhoei

Abstract
Aurantosides G−I (1−3) have been isolated from the lithistid sponge Theonella swinhoei from Papua New Guinea. Their structures were established by spectroscopic and chemical methods. Compounds 1−3 represent new monochloropentaenoyl tetramic acids with mono-, di-, and tri-N-saccharide substituents, respectively. Aurantosides G−I (1−3) failed to show any significant cytotoxicity against the human colon tumor cell line HCT-116.