6'7'-Epoxybergamottin is a furanocoumarin found in grapefruit. It is a potent inhibitor of the cytochrome P450 (CYP) isoform CYP3A4 with an IC50 value of 0.30 ppm in a cell-free assay, 0.33 μM in HL7 human liver cells, and 0.22 μM in S9 human intestine cells. It has been studied in the context of drug interactions with grapefruit constituents. It is found in grapefruit juice at concentrations of 0.1-7.4 μM and inhibits the transport of talinolol , a permeability glycoprotein (P-gp/ABCB1) transporter substrate, across Caco-2 cell monolayers (IC50 = 0.7 μM). 6'7'-Epoxybergamottin also has insecticidal properties with a concentration of 5 μg/cm2 leading to 100% mortality of adult olive fruit flies.