the essential oils (eos) from aerial parts of piper aduncum, p. callosuin and p. marginatum, collected from the amazon region of brazil, were analyzed by gc-ms and then evaluated for their antifungal and anticholinesterase activities. the essential oils were dominated by phenylpropanoids, such as dillapiole (73.0%) in p. aduncum, safrole (66.0%) in p. callosum and 3,4-methylenedioxypropiophenone (21.8%) in p. inarginatum. the analyzed oils showed low to moderate antifungal activity; with detection limits (dl) from 10 to 100 pg against cladosporium cladosporioides and c. sphareospermum. in the anticholinesterase (ache) evaluation, the oils of p. callosum (dl = 0.01 ng) and p. marginatum (dl = 0.01 ng) were one hundred times more potent than the standard physostigmine (dl = 1.0 ng). molecular docking analysis showed that phenylpropanoids docked reasonably well with acetyleholinesterase and may be responsible for the anti-ache activities of the piper eos. this is the first presentation about acetylcholinesterase inhibition by methylenedioxyphenyl-propanoids.