Eurocristatine, a new diketopiperazine dimer from the marine sponge-associated fungus Eurotium cristatum

A new diketopiperazine dimer, eurocristatine (1), was isolated, in addition to eight known metabolites including the anthraquinones erythroglaucin, physcion, catenarin, emodin and the dioxopiperazine alkaloids echinulin, neoechinulin A, neoechinulin E, variecolorin J, from the culture of the sponge-associated fungus Eurotium cristatum KUFC 7356. The structure of eurocristatine (1) was established based on 1D and 2D NMR spectral analysis as well as HRESIMS, and the absolute configuration of its stereogenic carbons was determined by an X-ray crystallographic analysis. Eurocristatine (1) did not exhibit cytotoxic, antibacterial or antifungal activity. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.