A METHOD FOR MEASURING NARINGENIN IN BIOLOGICAL-FLUIDS AND ITS DISPOSITION FROM GRAPEFRUIT JUICE BY MAN

The major flavonoid in grapefruit juice, naringin, has an aglycone, na ringenin, that inhibits some oxidations in vitro and may have in vivo activity. We developed an HPLC method to measure naringenin using a me thanol:water mobile phase with W absorbance detection. The recovery of naringenin was 96 %. Two subjects who drank grapefruit juice containi ng 214 mg naringin daily excreted approximately 30 mg/day of naringeni n glucuronide. Thus, naringin is hydrolyzed to naringenin and then con jugated with glucuronic acid prior to excretion of the conjugate.