homoisoflavonoids and the antioxidant activity of ophiopogon japonicus root

the root of ophiopogon japonicus has been used as a traditional chinese medicine and also a functional food ingredient for a long time in china. in the present study, 17 different homoisoflavonoid compounds were identified in the root extract of o. japonicus by hplc–dad and lcms/ms analyses. the antioxidant activity of the of chloroform/methanol (1:1, v/v), methanol and 70% ethanol extracts, and two major isolated homoisoflavonoid compounds (methylophiopogonanone a and methylophiopogonanone b) from o. japonicus root were investigated by various in vitro assays. methylophiopogonanone b showed the highest antioxidant ability according to four antioxidant methods. among the extracts, the chloroform/methanol extract which contained high amounts of homoisoflavonoids was found to exhibit the strongest antioxidant activity. the results showed that o. japonicus root can be regarded as a potential source of homoisoflavonoids and natural antioxidant.