Vulgaxanthins are a group of

betaxanthin Betalains are a class of red and yellow tyrosine-derived pigments found in plants of the order Caryophyllales, where they replace anthocyanin pigments. Betalains also occur in some higher order fungi. They are most often noticeable in the petals o ...

s, or the predominant yellow plant pigments found in red

beets The beetroot is the taproot portion of a beet plant, usually known in North America as beets while the vegetable is referred to as beetroot in British English, and also known as the table beet, garden beet, red beet, dinner beet or golden beet ...

, among other plants like ''

Mirabilis jalapa ''Mirabilis jalapa'', the marvel of Peru or four o'clock flower, is the most commonly grown ornamental species of ''Mirabilis'' plant, and is available in a range of colors. ''Mirabilis'' in Latin means wonderful and Jalapa (or Xalapa) is the st ...

'' and

swiss chard Chard or Swiss chard (; ''Beta vulgaris'' subsp. ''vulgaris'', Cicla Group and Flavescens Group) is a green leafy vegetable. In the cultivars of the Flavescens Group, the leaf stalks are large and often prepared separately from the leaf blade; ...

. They are

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

pigments, types I, II, III, IV, and V. Like all betaxanthins, they cannot be hydrolyzed by acid to

aglycone An aglycone (aglycon or genin) is the compound remaining after the glycosyl group on a glycoside is replaced by a hydrogen atom. For example, the aglycone of a cardiac glycoside would be a steroid molecule. Detection A way to identify aglycone ...

without degradation.

Water activity Water activity (''aw'') is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science, the standard state is most often defined as pure water at the same tempera ...

also affects stability of this antioxidant. It has been studied as a natural nutritional additive but instability remains a problem.

Reactions

*Vulgaxanthin-II +

Ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

NADH Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an aden ...

= Vulgaxanthin-I + NAD⁺ + H₂O *Vulgaxanthin-I + H₂O = Vulgaxanthin-II + Ammonia *Vulgaxanthin-II + ATP + Ammonia = Vulgaxanthin-I + ADP +

Orthophosphate A phosphoric acid, in the general sense, is a phosphorus oxoacid in which each phosphorus (P) atom is in the oxidation state +5, and is bonded to four oxygen (O) atoms, one of them through a double bond, arranged as the corners of a tetrahedron. ...

*Vulgaxanthin-II + ATP + Ammonia = Vulgaxanthin-I +

Diphosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among othe ...

5'-AMP Adenosine monophosphate (AMP), also known as 5'-adenylic acid, is a nucleotide. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine; it is an ester of phosphoric acid and the nucleoside adenosine. As a substituent it ...

* Betalamic acid +

L-Glutamine Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, ...

+ ATP = Vulgaxanthin-I + ADP + Orthophosphate

References

Biological pigments Food antioxidants Betalains {{organic-compound-stub

Reactions

See also

References