pelargonidin

Pelargonidin is an anthocyanidin, the aglycone component of many anthocyanins, a class of plant pigments responsible for red to orange colors in flowers and fruits. Pelargonidin itself occurs in several plant tissues and serves as the color core of pelargonidin glycosides, such as pelargonidin 3-glucoside, which are more common pigments in nature than the aglycone.

Natural occurrence: Pelargonidin-based pigments are characteristic of some red fruits and flowers, including strawberries, certain raspberries, and various red petals. The intensity and hue depend on pH, metal ions, and co-pigments.

Biosynthesis: In plants, pelargonidin is produced via the flavonoid branch of the phenylpropanoid pathway. It arises from dihydrokaempferol when the hydroxylation pattern on the B-ring is limited (lack of 3'-hydroxylase activity). The aglycone can be converted to glycosides by UDP-glucosyltransferases to form pelargonidin glycosides, which are the predominant natural pigments in many tissues.

Properties: Pelargonidin pigments are pH-sensitive, appearing red under acidic conditions and shifting toward orange or yellow as pH increases. They are also influenced by light, temperature, and metal ions. Glycosylation and acylation generally improve their stability relative to the aglycone.

Applications and health aspects: Pelargonidin-containing pigments contribute to the color of fruits and flowers and are studied as natural colorants in foods and cosmetics. They exhibit antioxidant activity in laboratory studies, and dietary pelargonidin glycosides are investigated for potential health effects, though evidence from human studies remains inconclusive.