Menthofuran is an organic compound found in a variety of essential oils including that of pennyroyal (Mentha pulegium). It is highly toxic and believed to be the primary toxin in pennyroyal responsible for its potentially fatal effects.[1] After ingestion of menthofuran, it is metabolically activated to chemically reactive intermediates that are hepatotoxic.[2]
Menthofuran can be synthesized from 5-methylcyclohexane-1,3-dione and allenyldimethylsulfonium bromide in two steps via a furannulation strategy consisting of enolate addition and rearrangement.[3]
Menthofuran is a metabolite of pulegone. Both in vitro and in vivo studies have found the pulegone metabolite menthofuran to be an inhibitor of CYP2A6.[4][5][6][7]
Menthofuran may deplete glutathione levels, leaving hepatocytes vulnerable to free radical damage.[5]