Cyclopenin is an inhibitor of acetylcholinesterase (AChE; IC50 = 2.04 μM for human recombinant AChE) that is produced by Penicillium. It exhibits greater than 2,000-fold selectivity over recombinant equine butyrylcholinesterase with an IC50 value greater than 4,080 μM. Cyclopenin also has antibacterial activity against E. coli and M. pyogenes.
