(E)- and (Z)-Foeniculin, Constituents of the Leaf Oil of a New Chemovariety of Clausena anisata

Abstract

The leaf oils of Clausena anisata Hook. f. collected from Pokuase, Ghana, were found to contain (E)-foeniculin as a major constituent (>78%) in 17 of 19 samples. (E)-anethole was the major constituent of the two other samples (57% and 67%) with (E)-foeniculin as the second most important compound (38% and 29%). The identity of the new natural product (Z)-foeniculin, present in small amounts (0.2-1.4%), was based on a comparison of retention indices and mass spectra with those of a synthesized sample whose spectroscopic data, reported here for the first time, are in agreement with the proposed structure. Two other minor constituents were identified as the rarely encountered natural products dictagymnin (1-20%) and 4-(3-methyl-2-butenyl)oxybenzaldehyde (0-0.2%).

Key Word Index:

• Clausena anisata
• Rutaceae
• essential oil composition
• chemotypes
• foeniculin isomers
• dictagymnin
• photoisomerization