Terpenoids and bisbibenzyls from Chinese liverworts Conocephalum conicum and Dumortiera hirsuta

Four new monoterpene esters, 2α,5β-dihydroxybornane-2-cinnamate (1), 2α,5β-dihydroxybornane-5-acetyl-2-cinnamate (2), 2α,5β-dihydroxybornane-2-p-hydroxycinnamate (3) and 2α,5β-dihydroxy-bornane-2-cis-p-hydroxycinnamate (4), together with a known compound 3,4-dimethoxystyrene (5) were isolated from Chinese liverwort Conocephalum conicum and six known compounds, 5,7-dihydroxycalamenene (6), 7-hydroxycalamenene (7), lunularin (8), riccardin C (9), marchantin C (10) and riccardin D (11) were isolated from Dumortiera hirsuta. Their structures were elucidated by extensive spectral analysis and chemical correlations. Compounds 1 and 8 showed moderate cytotoxicity against human HepG2 cells with IC₅₀ 4.5 μg/ml and 7.4 μg/ml, respectively, while compound 8 also showed antimicrobacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration at 64 μg/ml.