Isolation and characterization of dihydrohomoisoflavonoids from Portulaca oleracea L.

Eight pairs of dihydrohomoisoflavonoids ( 1 − 8 ), including four pairs of enantiomeric aglycones [( R, S )-portulacanones B ( 1 ) and C ( 2 ) and ( R, S )-oleracones C ( 3 ) and Q ( 4 )] and four pairs of epimeric glycosides [portulacasides A−D and epiportulacasides A−D ( 5 − 8 )], were obtained from Portulaca oleracea L. Among them, ( R, S )-oleracone Q ( 4 ) and four pairs of epimeric glycosides ( 5 − 8 ) were reported for the first time. The 50% EtOH fraction from the 70% EtOH extract prevented HepG2 human liver cancer cell damage induced by N -acetyl- p -aminophenol (APAP), and the cell survival rate was 62.3%. Portulacaside B ( 6a ), which was isolated from the 50% EtOH fraction, exhibited hepatoprotective and anti-inflammatory effects. The compound increased the survival rate of APAP-damaged HepG2 human liver cancer cells from 40.0% to 51.2% and reduced nitric oxide production in RAW 264.7 macrophages, resulting in an inhibitory rate of 46.8%.