Naringin

Naringin is a flavanone glycoside found predominantly in citrus fruits, especially grapefruits, and to a lesser extent in oranges, lemons, and limes. Chemically it is composed of the aglycone naringenin linked to the disaccharide neohesperidose. The compound is responsible for the characteristic bitter taste of many citrus varieties and is often measured in the food industry as an indicator of bitterness intensity.

The biosynthesis of naringin in plants involves the phenylpropanoid pathway, where phenylalanine is converted into naringenin, which is subsequently glycosylated by specific UDP‑glucosyltransferases. In humans, naringin is hydrolyzed by intestinal microbiota and hepatic enzymes to release naringenin, which can be absorbed and further metabolized into various conjugates.

Pharmacologically, naringin and its metabolite naringenin have attracted interest for their antioxidant, anti‑inflammatory, and lipid‑modulating activities observed in vitro and in animal studies. They appear to influence cytochrome P450 enzymes, particularly CYP3A4, leading to potential drug‑herb interactions; this is a notable concern when grapefruit products are consumed concomitantly with certain medications such as statins, calcium channel blockers, and some immunosuppressants.

Commercially, naringin is extracted for use as a natural flavoring agent, a dietary supplement, and a research standard. Analytical methods for quantifying naringin include high‑performance liquid chromatography (HPLC) and mass spectrometry, often coupled with UV detection. Regulatory agencies generally recognize naringin as safe (GRAS) when used within established limits in foods and beverages.