Valencene is a sesquiterpene that is an aroma component of citrus fruit and citrus-derived odorants.
It is obtained inexpensively from Valencia oranges.
[1] Valencene is biosynthesized from farnesyl pyrophosphate (FPP) by the CVS enzyme.
It is used as a precursor to nootkatone, the main contributor to the aroma and flavor of grapefruit.
[2][3]