Peonidin is an

O-methylated anthocyanidin The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups (methoxy bonds). O-methylation has an effect on the solubility of flavonoids. Enzymes O-methylated flavonoids formation implies the presence of spe ...

derived from

Cyanidin Cyanidin is a natural organic compound. It is a particular type of anthocyanidin (glycoside version called anthocyanins). It is a pigment found in many red berries including grapes, bilberry, blackberry, blueberry, cherry, chokeberry, cranber ...

, and a primary

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

. Peonidin gives purplish-red hues to flowers such as the peony, from which it takes its name, and roses. It is also present in some blue flowers, such as the

morning glory Morning glory (also written as morning-glory) is the common name for over 1,000 species of flowering plants in the family Convolvulaceae, whose current taxonomy and systematics are in flux. Morning glory species belong to many genera, some of ...

. Like most

anthocyanidins Anthocyanidins are common plant pigments, the sugar-free counterparts of anthocyanins. They are based on the flavylium cation, an oxonium ion, with various groups substituted for its hydrogen atoms. They generally change color from red throug ...

, it is pH sensitive, and changes from red to blue as pH rises because anthocyanidins are highly conjugated chromophores. When the pH is changed, the extent of the conjugation (of the double bonds) is altered, which alters the wavelength of light energy absorbed by the molecule. (Natural anthocyanidins are most stable in a very low pH environment; at pH 8.0, most become colorless.) At pH 2.0, peonidin is cherry red; at 3.0 a strong yellowish pink; at 5.0 it is grape red-purple; and at 8.0 it becomes deep blue; unlike many anthocyanidins, however, it is stable at higher pH, and has been isolated as a blue colorant from the brilliant "Heavenly Blue" morning glory (''Ipomoea tricolor Cav cv''). Because of its unusual color stability, a cafeyl-acylated buffered formulation of it has been patented for use as food coloring. Peonidin, like many anthocyanidins, has shown potent inhibitory and apoptotic effects on cancer cells ''in vitro'', notably metastatic human breast cancer cells. A very large question, however, has been raised about anthocyanidins' penetration and retention in human cells ''in vivo'', due to their rapid elimination from the human body. By far the greatest dietary source of peonidin is raw

cranberries Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. In Britain, cranberry may refer to the native species ''Vaccinium oxycoccos'', while in North America, cranberry ...

, which contain 42 mg per 100 g of fruit. Blueberries, plums, grapes, and cherries also contain significant amounts, ranging from 5 to 12 mg/100 g. Only fresh fruit has been shown to contain significant peonidin; frozen blueberries have been shown to contain almost none. Peonidin has been found in concentrations of up to 40 mg per 100 g (cooked) of certain cultivars of purple fleshed sweet potatoes; the amount of peonidin varies greatly across cultivars. It has also been isolated from raw black rice and black bananas. The higher level of peonidin in fresh fruit corresponds to the rule of thumb that more natural fruit is healthier. Specifically, the amount of phenolic compounds in cranberries has been found to be inversely correlated with fruit size and crop yield.

List of peonidin derivatives

* Peonidin-3-''O''-glucoside, found in red onion

References

{{Anthocyanins Nutrition O-methylated anthocyanidins Resorcinols