ANTIOXIDATIVE COMPONENTS, XANTHONE DERIVATIVES, IN SWERTIA-JAPONICA MAKINO

Substances with antioxidative properties were obtained from an ether e xtract of Swertia japonica Makino. Six active components of the extrac t were isolated and identified as methylbellidifolin, methylswertianin , swertianin, bellidifolin, norswertianin and desmethylbellidifolin. T hese six xanthone derivatives were shown to possess different antioxid ant activities by chemiluminescent assay. The antioxidative activities of bellidifolin, norswertianin and desmethylbellidifolin were higher than those of butylated hydroxytoluene (BHT) and a tocopherol. On auto xidation of methyl linoleate, bellidifolin had activity similar to tha t of BHT. On the basis of the data present on antioxidative properties and data reported on the mutagenicities of the xanthones, both activi ties were shown to give a good cor relation.