New amide alkaloids from Piper longum.

Bioassay-guided phytochemical investigation on Piper longum resulted in the isolation of two new compounds. By analyses of the MS, IR, UV, 1D and 2D NMR data, the two new compounds were identified as 3β, 4α-dihydroxy-1-(3-phenylpropanoyl)-piperidine-2-one (1) and (2E, 4E, 14Z)-6-hydroxyl-N-isobutyleicosa-2,4,14-trienamide (2). In vitro anti-HBV bioassay demonstrated compound 1 possessed remarkable activity suppressing the secretion of HBeAg in Hep G2.2.15 cell line, with an IC(50) value of 0.21mM and SI value of 16.4.