flawonoidem

A flavonoid is a diverse class of plant secondary metabolites belonging to the polyphenol family. They share a characteristic 15-carbon skeleton formed by two phenyl rings (A and B) connected by a three-carbon bridge that creates a heterocyclic C ring. Flavonoids occur as aglycones or as glycosides, where sugar moieties influence solubility and bioavailability.

Flavonoids are typically divided into several major subgroups, including flavones, flavonols, flavanones, isoflavones, anthocyanidins/anthocyanins, and flavan-3-ols (catechins). Each subgroup contains a range of compounds with distinct chemical structures and properties. They are widely distributed in fruits, vegetables, tea, wine, cocoa, and soy, often contributing to color and taste.

Biosynthesis of flavonoids proceeds via the phenylpropanoid pathway, starting from phenylalanine and involving enzymes such as chalcone synthase to build the core skeleton. Flavonoids have important roles in plants, including pigmentation, UV protection, pollen viability, and defense against pathogens and herbivores.

In humans, flavonoids are studied for potential health effects. They exhibit antioxidant and anti-inflammatory activities in laboratory settings, and epidemiological studies associate flavonoid-rich diets with various health benefits. However, clinical evidence for specific disease prevention is mixed, and bioavailability varies widely among compounds due to absorption, metabolism, and transformation by gut microbiota. After ingestion, flavonoids are often conjugated in the liver and excreted in urine or bile, with systemic levels influenced by food matrix and individual metabolism.

Uses of flavonoids include natural colorants, nutraceuticals, and functional foods. While generally safe as part of a balanced diet, high-dose supplements can interact with medications or affect enzyme systems, underscoring the need for evidence-based use.