Abstract
Some seeds of the Rutaceae family, Zanthoxylum piperitum, Z. schinifolium officinalis, Poncirus trifoliata, Citrus unshin, were investigated to clarify their antioxidative components. Finely powdered samples were extracted by hexane, followed by dichioromethane and then 70% methanol in a hot bath. Its unsaponifiables containing X-and Y-tocopherol with trace amount of ${\beta}-and$\;{\delta}-tocopherol$. also showed comparatively weak activity, although the hexane fraction itself had no significant antioxidative effect on lard. Levels of total tocopherols in the samples averages 42. 24-154. 11 mg/lOOg total extractives. The dichloromethane-and 70% methanol extractives showed strong antioxidative activity, from which antioxidative substances were purified with benzene-acetone(6:5, V/V) on a silica gel column, and with a solvent mixture of acetonitrile-methanol-$H_2O$(40:40:20, V/V/V) on a Sep-Pak $C_{18}$ hydrolyzed by 5% KOH-ethanol. The recovered unsaponifiables were, then, separated on a column of high performance liquid chromatography. The unsaponifiables produced by hydrolysis of the isolates from dichloromethane extractives has epi-catechin(40.0-57.1%) and (+)-catechin<$l9.1{\sim}24.4%$ to total phenolic substances, on area base) as major component, accompanied by chlorogenic acid, gallic acid(?), trans-p-coumaric acid and tralls-p-ferulic acid including some unknown components, and those derived from 70% methanol extractives also comprise (+)-catechin($31.3{\sim}39.6%$ to total components, on area base), epi-catechin($2O.2{\sim}36.4%$), trans-p-cournaric acid(8.4-15.3%) and trans-p-ferulic acid($7.7{\sim}14.1%$) as predominant component with some minor coponents, but the fraction supposed to be gallic acid(?) is not present. The antioxidative activities of the phenolic components isolated in this work were in order of epi-catechin>catechin>chlorogenic acid>trans-p-ferluic acid>trans-p-coumaric acid.