<p>Two new lignan compounds, 5′-allyl-2,2′-dihydroxy-[1,1′-biphenyl]-5-carboxylic acid (<b>1</b>) and 4,4′-diallyl-[1,1′-biphenyl]-2,2′-diol (<b>2</b>), together with four known compounds (<b>3–6</b>), were isolated from the barks of <i>Sassafras tzumu</i>. The new compounds were determined by NMR (<sup>1</sup>H and <sup>13</sup>C NMR, HSQC, HMBC, <sup>1</sup>H-<sup>1</sup>H COSY, NOESY/ROESY), and MS analysis. Compounds <b>1–3</b> showed potent AChE inhibitory activities, with IC<sub>50</sub> values of 2.00, 1.81 and 1.91 μM, respectively.</p
