Biosynthesis of phenylpropanoid compounds. Part II. Incorporation of specifically labelled cinnamic acids into eugenol

Abstract

Experiments on the incorporation in Ocimum basilicum L. of specifically labelled cinnamic acids have shown that in the biosynthesis of eugenol (i) cinnamic acid is a necessary intermediate, (ii) the carboxylic carbon atom of cinnamic acid is lost and an extra one-carbon unit is introduced into the allyl group, and (iii) both the olefinic hydrogen atoms of the cinnamic acid side-chain remain in their original position. These results can be explained on the basis of a new biogenetic hypothesis.