Bioactivity-guided isolation of biphenanthrenes from Liparis nervosa

Abstract Three new biphenanthrenes, Liparisphenanthrenes A–C ( 1 – 3 ), along with three known ones were obtained from the ethanolic extract of Liparis nervosa (Orchidaceae) by bioactivity-guided fractionation. Their structures were elucidated on the basis of extensive spectroscopic analysis. All the compounds obtained were tested in vitro for cytotoxic activities against stomach (HGC-27) and colon (HT-29) cancer cell lines. 1 , 4 and 5 showed potent cytotoxicities to HGC-27 cell line with IC 50 values of 8.21–9.95 μmol/L, and 1 and 5 also exhibited potent cytotoxic activities to HT-29 cell line with IC 50 values of 8.53–9.27 μmol/L.