Aurantoside J: a new tetramic acid glycoside from Theonella swinhoei. Insights into the antifungal potential of aurantosides.

The chemical investigation of an Indonesian specimen of Theonella swinhoei afforded four aurantosides, one of which, aurantoside J (5), is a new compound. The structure of this metabolite, exhibiting the unprecedented N-α-glycosidic linkage between the pentose and the tetramate units, has been determined through detailed spectroscopic analysis. The four obtained aurantosides have been tested against five fungal strains (four Candida and one Fusarium) responsible of invasive infections in immuno-compromised patients.

Dehydroconicasterol and aurantoic acid, a chlorinated polyene derivative, from the Indonesian sponge Theonella swinhoei.

The chlorinated polyene aurantoic acid (1) and the 4-methylene sterol dehydroconicasterol (2) were isolated from the Indonesian sponge Theonella swinhoei, and their structures were elucidated by interpretation of spectroscopic data. Aurantoic acid is a unique member in the class of naturally occurring conjugated polyene derivatives, while dehydroconicasterol is the likely biogenetic precursor of the major Theonella 4-methylene sterols.