anthocyaninen

Anthocyaninen, in English anthocyanins, are a group of water-soluble pigments belonging to the flavonoid class. They are glycosides of anthocyanidins and are responsible for red, purple, and blue colors in many fruits, vegetables, and flowers. Common anthocyanidins include cyanidin, delphinidin, pelargonidin, peonidin, malvidin and petunidin. Glycosylation and acylation diversify their chemical forms, which are typically located in the vacuoles of plant cells. Their color is highly pH-dependent: acidic conditions produce red hues, while alkaline conditions shift toward blue; chelation with metal ions can also modulate color.

Anthocyanins are widely distributed in the plant kingdom, with high concentrations in berries (blueberries, blackberries, raspberries), grapes, cherries, plums, red cabbage, purple corn and red onions. They contribute to visual signals used in pollination and fruit dispersal and may play roles in photoprotection and antioxidative defense within the plant.

Biosynthesis proceeds via the phenylpropanoid pathway, eventually forming the anthocyanidin skeleton, which is glycosylated by UDP-glucose-dependent enzymes to produce the stable anthocyanins. Further acylation increases stability. The pigments accumulate in the vacuole after transport by specific transport proteins.

In humans, dietary anthocyanins exhibit antioxidant activity in vitro and are studied for potential health effects, including anti-inflammatory and cardiovascular benefits. Bioavailability is limited and varies with food matrix and metabolism; effects observed in dietary studies are modest and often inconclusive. Anthocyanins are also used as natural colorants in foods and cosmetics.