The synthesis and anti-acetylcholinesterase activities of (+)-physostigmine and (+)-physovenine

Abstract (+)-Physostigmine and (+)-physovenine have been synthesized. The anti-acetylcholinesterase activities of these two bases, which have been investigated in vitro using erythrocyte acetylcholinesterase, have been found to be much lower than the corresponding activities of the alkaloids (-)-physostigmine and (-)-physovenine. Possible reasons for these activity differences are discussed.