Co-occurrence of (-) and (+)-germacrene-D in Solidago altissima L.: Determination of the optical rotation of optically pure germacrene-D.

Germacrene-D, which has sexual attractant properties similar to those of periplanone-B, has been isolated in an optically impure state from many plants, i.e., (-) and (+)-germacrene-D co-occur in different ratios in various plants. (-)-Germacrene-D isolated from Solidago altissima L. in this work was determined to have an optical purity of 18.0%. In addition, the optical rotation of optically pure germacrene-D was estimated to be 305°.