For example excellent AChE inhibitors such as physostigmine and the more recent addition, galanthamine and huperzine A were isolated from Physostigma
venenosum, Galanthus species and Huperzia serrata, respectively (Hostettmann et al.
Eserine [(3 [Alpha],S-[Alpha])-1,2,3,3 [Alpha],8,8 [Alpha]-Hexahydro-1,3 [Alpha],8-trimethylpyrrolo (2,3-b) indol-5-ol methylcarbamate] is an ester obtained from calabar beans, the seeds of the vine Physostigma
Several other members are Melilotus, Copaiva, Physostigma
, Lathyrus, Indigo, Chrysarobin urn, Trifolium repens, Robinia, and Mimosa pudica.
Physostigma venenosum was used traditionally in Africa as a ritual poison, claimed to determine the guilt or innocence of person accused of a crime.
Along with the prototype inhibitor of AChE physostigmine, obtained from the plant Physostigma venenosum, other molecules with highly significant anti-cholinesterase activity are huper-zine-A, galantamine, [alpha]-viniferin and ursolic acid obtained from Huperzia serrata, Galanthus nivalis and Narcissus sp.