Lignans and phenols with potential anti-inflammatory effect from the stems of Mallotus paxii Pamp.

Phytochemical investigation of the stems of Mallotus paxii Pamp. led to the isolation and identification of four new compounds, including three neolignans (1-3) and one phenol (13), along with eight known neolignans (4-12) and one known phenol (14). Their structures were determined by spectroscopic methods, including NMR, MS and ECD analyses. Bioassay demonstrated that malloapelin A (4) exhibited a most potent anti-inflammatory activity to NO release with IC50 value of 21.32 μM. Furthermore, malloapelin A (4) markedly decreased the secretion of TNF-α, iNOS, and NF-κB and inhibited the expression of COX-2 and NF-κB/p65 in LPS-induced RAW264.7 cells in a dose-dependent manner.