Lignans from the bark of Zanthoxylum simulans

Investigation on the EtOAc extract of the bark of Zanthoxylum simulans led to the isolation of four new lignans including zanthoxylumin A (1), zanthoxylumin B (2), (-)-magnolin (3), and (-)-pinoresinol-di-3,3-dimethylallyl ether (4). Their structures were established by comprehensive analysis of the spectral data, especially 1D and 2D NMR spectra.