Terreulactones A, B, C, and D: novel acetylcholinesterase inhibitors produced by Aspergillus terreus. I. Taxonomy, fermentation, isolation and biological activities

In the course of screening for selective inhibitors of acetylcholinesterase from the microbial metabolites, four new meroterpenoid compounds, terreulactones A, B, C and D were isolated from solid state fermentation of Aspergillus terreus Fb000501. They showed potent inhibitory activities against acetylcholinesterase with IC50 values in range of 0.06 to approximately 0.42 microM. In addition, they exhibited more than 500 to approximately 3000 times selectivity for acetylcholinesterase compared with butyrylcholinesterase.