Pulegone

Pulegone is a naturally occurring organic compound obtained from the essential oils of a variety of plants such as Nepeta cataria, Mentha piperita, and pennyroyal. It is classified as a monoterpenoid, which means that it is an oxidized derivative of a terpene, a large class of naturally occurring C₁₀ hydrocarbons.
Pulegone is a colorless oil with a pleasant odor similar to pennyroyal, peppermint, and camphor. It is used in flavoring agents, in perfumery, and in aromatherapy.

Isolation and some uses

Pulegone comprises 75% of the oil pressed from pennyroyal, which is cultivated for that purpose. Hydrogenation of pulegone gives menthone. Pulegone is also a precursor to menthofuran, another flavorant.

Biochemistry

The enzyme -pulegone reductase from peppermint catalyses a reduction reaction which gives a mixture of -menthone and -isomenthone:
It uses nicotinamide adenine dinucleotide phosphate as its cofactor.

Toxicology

It was reported that the chemical is toxic to rats if a large quantity is consumed.
Pulegone is also an insecticide − the most powerful of three insecticides naturally occurring in many mint species.
As of October 2018, the FDA withdrew authorization for the use of pulegone as a synthetic flavoring substance for use in food, but that naturally occurring pulegone can continue to be used.