The allergens of Dendropanax trifidus Makino and Fatsia japonica Decne. et Planch. and evaluation of cross-reactions with other plants of the Araliaceae family.

cis-9,17-Octadecadiene-12,14-diyne-1,16-diol (I), an analog of falcarinol has been identified in our previous report as an active component of Dendropanax trifidus and a strong sensitizer. In this report, 16-hydroxy-cis-9,17-octadecadiene-12,14-diynoic acid (II) and cis-9,trans-16-octadecadiene-12,14-diynoic acid (III) were elucidated as 2 other active components of the plant. Compound I, however, presented with the highest concentration and showed a stronger reaction on patch testing. The leaves of Fatsia japonica Decne. et Planch. were also found to contain compound I, but the amount was found to be 7x more in Dendropanax trifidus than in Fatsia japonica. 5 subjects with hypersensitivity to Dendropanax trifidus and compound I showed positive reactions when patch tested with the leaves of Hedera helix L. and Schefflera arboricola. 1 of these also showed a positive reaction to the extract of Panax ginseng root powder diluted 1% in ethanol. There was cross-reaction among these plants, which all belong to the Araliaceae family.