(-)-Epicatechin derivate from Orostachys japonicus as potential inhibitor of the human butyrylcholinesterase.

Cholinesterase inhibitors block the bioconversion of neurotransmitters by cholinesterase in the nervous system. Epicatechin derivatives (1, 3 and 5), polyphenols (6 and 7) from Orostachys japonicus, and catechin derivatives (2 and 4) from our in-house library were evaluated for their inhibitory activity on cholinesterase. Compound 5 exhibited IC50 values of 58.3±2.4 and 17.8±3.8μg/mL on AChE and BuChE, respectively. Compound 5 inhibited BuChE more strongly than AChE through a competitive behavior. In silico binding positions of 5 in the active site were predicted using Autodock 4.2 and processed in a 10000-ps molecular dynamics simulation to assess the stability of compound 5 binding.