<div><p>Two new cadinane-type sesquiterpenes, frullanic acid (<b>1</b>) and frullanic acid methyl ester (<b>2</b>), together with four known bibenzyls, brittonin B (<b>3</b>), 3,3′-dimethoxy-4,5-methylenedioxybibenzyl (<b>4</b>), 3,4,5,3′,4′-penlamethoxybibenzyl (<b>5</b>) and ( ± )-3-(4′-methoxybenzyl)-5,6-dimethoxyphtbalide (<b>6</b>), were isolated from the Chinese liverwort <i>Frullania serrata</i>. The structures of the new metabolites were elucidated by analysing the spectroscopic data (1D NMR, 2D NMR, HR-ESI-MS and IR). The absolute configurations of compounds <b>1</b> and <b>2</b> were determined by comparing the experimental and calculated electronic circular dichroism spectra predicted by using time-dependent density functional theory as well as the CD exciton chirality method.</p></div
