Effect of maturity, processing, and storage on the furanocoumarin composition of grapefruit and grapefruit juice.

Since the early 1990's, grapefruit juice has been implicated in drug interaction with various furanocoumarins (FCs) now associated with the effect. Although FCs are present in various fruits and vegetables, it is their presence in grapefruit that has attracted the most attention. Studies have shown that FCs in grapefruit juice can vary significantly and from multiple causes.

New furanocoumarins detected from grapefruit juice retentate.

Grapefruit (Citrus paradisi Macf.) furanocoumarins and related compounds have been shown to interact with the enterocyte cytochrome P450, CYP3A4, and as a result they affect the bioavailibility of certain drugs. Only a few grapefruit furanocoumarins have been identified so far.