A cytotoxic pyrrolidinoindoline diketopiperazine dimer from the algal fungus Eurotium herbariorum HT-2

A new cytotoxic pyrrolidinoindoline diketopiperazine dimer, cristatumin E (1), was isolated from the fermentation broth of the algal fungus Eurotium herbariorum HT-2 associated with the marine algae, Enteromorpha prolifera. The structure was determined by spectroscopic analyses and Marfey's amino acid analysis. Cristatumin E (1) showed cytotoxicity against K562 tumor cell line and antibacterial activity against Enterobacter aerogenes and Escherichia coli with IC50 and MIC values of 8.3, 44.0 and 44.0 mu mol/L, respectively. (C) 2013 Wei-Ming Zhu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.