Homoisoflavonoids from Ophiopogon japonicus and Its Oxygen Free Radicals (OFRs) Scavenging Effects

ABSTRACTAIMTo investigate the OFRs scavenging activities of homoisoflavonoids from the fibrous root of Ophiopogon japonicus.METHODSThe scavenging effect of homoisoflavonoids isolated from O. japonicus extracts was examined on superoxide anion (O2·−), hydroxyl radical (·OH), and hydrogen peroxide (H2O2) by chemiluminescence.RESULTSTen homoisoflavonoids were obtained from O. japonicus extracts. They were identified as methylophiopogonanone A (1), methylophiopogonanone B (2), ophiopogonanone A (3), ophiopogonanone E (4), 5, 7-dihydroxy-6, 8-dimethyl-3-(4′-hydroxy-3′, 5′-methoxybenzyl) chroman-4-one (5), methylophiopogonone A (6), methylophiopogonone B (7), desmethylisoophiopogonone B (8), 5, 7, 2′-trihydroxy-8-methyl-3-(3′, 4′-methylenedioxybenzyl) chromone (9) and 5, 7, 2′-trihydroxy-6, 8-dimethyl-3-(3′, 4′-methylenedioxybenzyl) chromone (10).CONCLUSIONCompounds 8 and 9 were firstly isolated from O. japonicus. The majority of homoisoflavonoids could scavenge ·OH and H2O2 in vitro to a certain extent, and their bioactivities should be related with the respective structures.