Localization and contents of paradisins, the most potent CYP3A4 inhibitors, in grapefruit Citrus paradisii and grapefruit juice

Paradisins A-C originally isolated from grapefruit juice are found to be the most potent CYP3A4 inhibitors discovered so far. The presence of the intact paradisins was confirmed in the unprocessed fruit Citrus paradisii. In commercially available grapefruit juice, paradisins localized only in the pale yellow solid (pulp) but not in pulp-free liquid. Although the contents of paradisins A and B in juice were almost the same as that in unprocessed fruit, the content of paradisin C in juice was one-tenth of that in unprocessed fruit because of its instability.