Dihydroxybergamottin caproate as a potent and stable CYP3A4 inhibitor.

We investigated the inhibitory activity of the furanocoumarin derivatives from grapefruit juice to the drug metabolizing enzyme, cytochrome P450 (CYP) 3A4. Although two known furanocoumarin dimers GF-I-1 (1) and GF-I-4 (2) showed potent CYP3A4 inhibition with IC50 value of 0.07 microM, a semi-synthetic dihydroxybergamottin caproate (11), which was more stable and more simple than the dimers, exhibited comparable activity against CYP3A4.