Bergamottin

Furanocoumarins are organic compounds found in the seeds and fruits of many species of plants, notably in the families Rutaceae (citrus fruits) and Apiaceae (celery, carrots, and others). As the name suggests, the central structure of furanocoumarins consists of a furan ring fused to a two-ring coumarin system.

Psoralen¹ and angelicin² are unsubstituted furanocoumarins in which the furan and coumarin rings are fused in linear and angular orientations, respectively. Bergamottin and its oxidation products 6′,7′-dihydroxybergamottin³ (DHB) and 6′,7′-epoxybergamottin⁴ are psoralen derivatives that have geraniol-derived side chains attached at the 5-position. Bergamottin is named after the bergamot orange (Citrus bergamia); it was first isolated from bergamot oil in 1937 by Ernst Späth and Paul Kainrath at the University of Vienna.

Bergamottin plays a role in the lives of many people. It and DHB inhibit the cytochrome P450 enzyme CYP3A, thereby slowing or preventing the metabolism of lovastatin, simvastatin, atorvastatin, and other “statin” drugs that decrease the formation of low-density lipoprotein (LDL) carriers of cholesterol in the body. Bergamottins are particularly abundant in grapefruit, which is why statin labels advise against consumption of the fruit or its juice close to the time the drugs are taken.

The oxidized bergamottins and other grapefruit ingredients also inhibit the transport of talinolol⁵, a substrate for P glycoprotein, an important cell membrane component that removes foreign substances from cells. For more information on bergamottin and its derivatives, see this Science Direct entry.

1. CAS Reg. No. 66-97-7.
2. CAS Reg. No. 523-50-2.
3. CAS Reg. No. 145414-76-2.
4. CAS Reg. No. 206978-14-5.
5. CAS Reg. No.57460-41-0.