A new conjugated amide-dimer from the aerial parts of Piper submultinerve.

Bioassay-guided fractionation and purification of the aerial parts of Piper submultinerve led to the isolation of a new conjugated amide-dimer, submultinamide A (1), along with 11 known compounds. The structures were determined on the basis of spectroscopic methods. Among the tested compounds, pellitorine (2), guineensine (4), N-benzylcinnamide (6) and aristolactam BII (8) showed significant activities in the anti-syncytium assay using (ΔTat/Rev)MC99 virus and 1A2 cell line system, whereas 2 was most active (EC₅₀ 35.1 µM and selectivity index 4.7). In the HIV-1 reverse transcriptase assay, only 4 was active with IC₅₀ 50.8 µM.