Pinoresinol


Pinoresinol is a lignan found in Styrax sp. and in Forsythia suspensa. It is also found in the caterpillar of the cabbage butterfly, Pieris rapae where it serves as a defence against ants.
In food, it is found in sesame seed, in Brassica vegetables and in olive oil.

Biosynthesis

A first dirigent protein was discovered in Forsythia intermedia. This protein has been found to direct the stereoselective biosynthesis of -pinoresinol from coniferyl alcohol monomers. Recently, a second, enantiocomplementary dirigent protein was identified in Arabidopsis thaliana, which directs enantioselective synthesis of -pinoresinol.

Pharmacology

Pinoresinol inhibits the enzyme α-glucosidase in vitro and may therefore act as a hypoglycemic agent. A study involving extra virgin olive oil showed that pinoresinol possess in vitro chemoprevention properties. Increased apoptosis and cellular arrest at the G2/M stage in p53-proficient cells occurred.

Metabolism into enterolignans

Pinoresinol, along with other plant lignans, are converted into enterolignans by intestinal microflora in the human body.