Sesame lignans, whose biosynthetic pathway is the subject of this study, have well-
established antioxidant and health protecting properties. Using a combination of radio-and
stable-isotopically labelled precursor administration experiments, it was demonstrated that E-
coniferyl alcohol undergoes stereoselective coupling to afford (+)-pinoresinol in Sesamum
indicum seeds. Only this enantiomer, and not its (−)-antipode, is metabolized further in
maturing seeds to afford (+)-piperitol,(+)-sesamin, and (+)-sesamolin. Introduction of the …