A New Ergosterol Analog, a New Bis-Anthraquinone and Anti-Obesity Activity of Anthraquinones from the Marine Sponge-Associated Fungus Talaromyces stipitatus KUFA 0207.

A new ergosterol analog, talarosterone ( 1 ) and a new bis -anthraquinone derivative ( 3 ) were isolated, together with ten known compounds including palmitic acid, ergosta-4,6,8(14),22-tetraen-3-one, ergosterol-5,8-endoperoxide, cyathisterone ( 2 ), emodin ( 4a ), questinol ( 4b ), citreorosein ( 4c ), fallacinol ( 4d ), rheoemodin ( 4e ) and secalonic acid A ( 5 ), from the ethyl acetate extract of the culture of the marine sponge-associated fungus Talaromyces stipitatus KUFA 0207. The structures of the new compounds were established based on extensive 1D and 2D spectral analysis, and in the case of talarosterone ( 1 ), the absolute configurations of its stereogenic carbons were determined by X-ray crystallographic analysis. The structure and stereochemistry of cyathisterone ( 2 ) was also confirmed by X-ray analysis. The anthraquinones 4a - e and secalonic acid A ( 5 ) were tested for their anti-obesity activity using the zebrafish Nile red assay. Only citreorosein ( 4c ) and questinol ( 4b ) exhibited significant anti-obesity activity, while emodin ( 4a ) and secalonic acid A ( 5 ) caused toxicity (death) for all exposed zebrafish larvae after 24 h.