Citrus And Statins

“How Foods and Drugs Collide” provided my first knowledge that 5-geranoxy psoralen (bergamottin) had been identified as the active agent in grapefruit juice implicated in interfering with the so-called statin drugs (C&EN, Sept. 27, page 55).

In the 1950s and ’60s at the Fruit & Vegetable Laboratory in Pasadena, Calif. (a branch lab of the USDA Western Regional Research Center), my research group made a comprehensive study of the substituted coumarins and psoralens in citrus peel oils with primary interest in lemon oil for the purpose of identification. A table summarizing the compounds found in lemon, lime, grapefruit, bergamot, and bitter orange peel oils is given in the final paper of this study titled “Psoralens and Substituted Coumarins from Expressed Oil of Lime” (Phytochemistry 1967, 6, 585). Bergamottin was identified in lemon, lime, and bergamot peel oils. Two substituted psoralens were found in grapefruit peel oil but in amounts too small for positive identification. One of these may have been bergamottin.

Because the amount of dissolved solids in lime oil was so much higher in lime than the other oils, we made a record of recovery amounts by column chromatography. By far the most abundant compound was bergamottin, more than 3% by weight of the oil. Knowing this, I would not recommend adding a twist of lime peel to a drink for a person using a statin drug (such as Lipitor).

William L. Stanley
Carmel, Calif.