flavanoneihin

Flavanones are a subclass of flavonoids, natural phenolic compounds produced by plants. They share the typical flavonoid carbon skeleton (a C6-C3-C6 framework) but have a saturated heterocyclic ring, lacking the C2-C3 double bond seen in flavones. The aglycone core is 2,3-dihydro-2-phenylchromen-4-one, and various substitutions on the A and B rings give rise to different flavanones.

Biosynthesis proceeds in plants from p-coumaroyl-CoA and malonyl-CoA via the type III polyketide pathway. Chalcone synthase forms chalcone, which is then isomerized by chalcone isomerase to the flavanone scaffold. Subsequent enzymatic hydroxylations and methylations generate the diversity of flavanones found in nature.

Natural occurrence and examples: The most well-known flavanones include naringenin, hesperetin, eriodictyol, pinocembrin, and isosakuranetin. They commonly occur as glycosides in plants; for example, naringenin glycosides (like naringin) and hesperetin glycosides (like hesperidin) are abundant in citrus fruits. Pinocembrin is found in honey and propolis.

Biological activity and uses: Flavanones exhibit antioxidant activity and have been studied for anti-inflammatory, antimicrobial, and potential cardioprotective effects. Glycosides are typically less active than their aglycones and are often hydrolyzed during digestion to release the active aglycone. In food chemistry, flavanones can influence flavor and bitterness, and citrus-derived flavanones are of interest for nutraceutical research.

Analytical context: Flavanones and their glycosides are commonly analyzed by high-performance liquid chromatography and mass spectrometry to determine composition in plant extracts and foods.