Diversification of cytochrome P450 monooxygenases (P450s) is thought to result from antagonistic interactions between plants and their herbivorous enemies. However, little direct evidence demonstrates the relationship between selection by plant toxins and adaptive changes in herbivore P450s. Here we show that the furanocoumarin-metabolic activity of CYP6B proteins in two species of swallowtail ...

Our previous study indicated that formation of furanocoumarin phytoalexins could be induced in Glehnia littoralis root cultures by treatment with 10-40 mM ascorbic acid (AsA). This furanocoumarin production is much less evident when G. littoralis roots are treated with AsA under iron-deficient conditions. Instead, two large unknown peaks appeared in the HPLC chromatogram, whose chemical structu...

Fractionation of petroleum ether partitioned ethanol extract and crude petroleum ether extract of the leaves of Murraya koenigii Linn (Rutaceae) led to the isolation of 5,8-dimethyl furanocoumarin (1) and 1-al, 3[6’, 6’ dimethyl 5-hexene] carbazole (2) and β-sitosterol (3). Their structures were elucidated by spectroscopic methods such as UV, IR, NMR and LCMS. All the compounds were isolated fo...

BACKGROUND Grapefruit juice (GFJ) enhances the systemic exposure of numerous CYP3A4 drug substrates, including felodipine, by inhibiting intestinal (but not hepatic) first-pass metabolism. Furanocoumarins have been identified as major CYP3A4 inhibitors contained in the juice, but their contribution to the GFJ effect in vivo remains unclear. OBJECTIVE To ascertain whether furanocoumarins media...

Furanocoumarins represent plant toxins that are used in the treatment of a variety of skin diseases and are metabolized by cytochrome p450 monooxygenases (p450s) existing in insects such as Papilio polyxenes (the black swallowtail). To elucidate the active site in the CYP6B1 protein that is the principal p450 existing in this species, we have constructed a homology model of it based on sequence...

A rapid and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been used for determination of furanocoumarins in methanolic extracts of Peucedanum tauricum Bieb. HPLC separation was performed on a C18 analytical column (250 mm × 4 mm i.d., 5-μm particles) with a methanol–water gradient as mobile phase. A second chromatographic system with an acetonitrile–water...