Naringenin

Naringenin is a bitter, colourless flavanone, a type of flavonoid. It is the predominant flavanone in grapefruit, and is found in a variety of fruits and herbs. Naringenin is a bitter, colourless flavanone, a type of flavonoid. It is the predominant flavanone in grapefruit, and is found in a variety of fruits and herbs. Naringenin has the skeleton structure of a flavanone with three hydroxy groups at the 4', 5, and 7 carbons. It may be found both in the aglycol form, naringenin, or in its glycosidic form, naringin, which has the addition of the disaccharide neohesperidose attached via a glycosidic linkage at carbon 7. Like the majority of flavanones, naringenin has a single chiral center at carbon 2, resulting in enantiomeric forms of the compound. The enantiomers are found in varying ratios in natural sources. Racemization of S(-)-naringenin has been shown to occur fairly quickly. Naringenin has been shown to be resistant to enatiomerization over pH 9-11. Separation and analysis of the enantiomers has been explored for over 20 years, primarily via high-performance liquid chromatography on polysaccharide-derived chiral stationary phases. There is evidence to suggest stereospecific pharmacokinetics and pharmacodynamics profiles, which has been proposed to be an explanation for the wide variety in naringenin's reported bioactivity. Naringenin and its glycoside has been found in a variety of herbs and fruits, including grapefruit, bergamot, sour orange, tart cherries, tomatoes, cocoa, Greek oregano, water mint, drynaria as well as in beans. Ratios of naringenin to naringin vary among sources, as do enantiomeric ratios. This bioflavonoid is difficult to absorb on oral ingestion. In the best-case scenario, only 15% of ingested naringenin will get absorbed in the human gastrointestinal tract. The naringenin-7-glucoside form seems less bioavailable than the aglycol form. Grapefruit juice can provide much higher plasma concentrations of naringenin than orange juice. Also found in grapefruit is the related compound kaempferol, which has a hydroxyl group next to the ketone group. Naringenin can be absorbed from cooked tomato paste.