Anthocyanin

A class of compounds with antioxidant properties found in plants

Anthocyanins are a class of flavonoids that are responsible for the red, purple, and blue colors in many fruits, vegetables, and flowers. These pigments are water-soluble and are found in the vacuole of plant cells. Anthocyanins play a significant role in plant physiology and have been studied for their potential health benefits in humans.

Structure and Biosynthesis

Anthocyanins are glycosides of anthocyanidins, which are derived from the flavonoid biosynthetic pathway. The basic structure of an anthocyanin consists of an anthocyanidin aglycone linked to one or more sugar molecules. The most common sugars attached to anthocyanidins are glucose, rhamnose, and galactose.

The biosynthesis of anthocyanins begins with the amino acid phenylalanine, which is converted into cinnamic acid by the enzyme phenylalanine ammonia-lyase. This is followed by a series of enzymatic reactions that lead to the formation of the anthocyanidin structure. The final step involves the attachment of sugar molecules, which increases the solubility and stability of the pigment.

Functions in Plants

Anthocyanins serve several functions in plants, including:

• Attracting pollinators: The vibrant colors of anthocyanins attract pollinators such as bees and butterflies, aiding in the reproductive process of flowering plants.
• Protection against UV radiation: Anthocyanins absorb ultraviolet light, protecting plant tissues from damage caused by excessive sunlight.
• Defense against herbivores and pathogens: The presence of anthocyanins can deter herbivores and inhibit the growth of certain pathogens.

Sources of Anthocyanins

Anthocyanins are abundant in a variety of fruits and vegetables, including:

• Berries: Blueberries, blackberries, raspberries, and strawberries are rich sources of anthocyanins.
• Grapes: Both red and purple grapes contain significant amounts of these pigments.
• Red cabbage: Known for its deep purple color, red cabbage is a vegetable high in anthocyanins.
• Eggplant: The skin of eggplants contains anthocyanins, contributing to its dark purple hue.

Blueberries are a rich source of anthocyanins.

Health Benefits

Anthocyanins have been studied for their potential health benefits, which include:

• Antioxidant properties: Anthocyanins can neutralize free radicals, reducing oxidative stress and potentially lowering the risk of chronic diseases.
• Anti-inflammatory effects: These compounds may help reduce inflammation, which is linked to various health conditions such as cardiovascular disease and arthritis.
• Improved vision: Some studies suggest that anthocyanins can enhance visual acuity and protect against age-related eye disorders.

Related Pages

• Flavonoid
• Antioxidant
• Phenolic compound
• Plant pigment

Red cabbage is high in anthocyanins, giving it a distinctive color.