Antifungal piperolides from Piper malacophyllum (Prels) C. DC

Bioactivity- guided fractionation of the CH2Cl2 extract from leaves of Piper malacophyllum using bioautography assay against fungi, led to the isolation of two known bioactive piperolides: 4,6- dimethoxy- 5- E- phenylbutenolide ( 1) and 4,6- dimethoxy- 5- Z- phenylbutenolide ( 2). IR, MS and NMR spectroscopic data were used for the identification of these compounds including comparison with previously reported data. The E configuration is associated to higher activity for compound 1, since the minimum amount required for the growth inhibition of Cladosporium cladosporioides and C. sphaerospermum were 1.0/ 1.0 mu g ( 1) and 5.0/ 10.0 mu g ( 2), respectively.