Vulgaxanthins are a group of betaxanthins, or the predominant yellow plant pigments found in red beets, among other plants like Mirabilis jalapa

Mirabilis jalapa

Mirabilis jalapa is the most commonly grown ornamental species of Mirabilis, and is available in a range of colours. Mirabilis in Latin means wonderful and Jalapa is a town in Mexico...

and swiss chard. They are antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

 pigments, types I, II, III, IV, and V. Like all betaxanthins, it cannot be hydrolyzed by aglycone

Aglycone

An aglycone is the non-sugar compound remaining after replacement of the glycosyl group from a glycoside by a hydrogen atom. The spelling aglycon is sometimes encountered .Classes of phytochemicals found in the aglycone and glycosides forms :...

 without degradation. Water activity

Water activity

Water activity or aw was developed to account for the intensity with which water associates with various non-aqueous constituents and solids. Simply stated, it is a measure of the energy status of the water in a system...

 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
  Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
  
   + NADH = Vulgaxanthin-I + NAD⁺
  Nicotinamide adenine dinucleotide
  Nicotinamide adenine dinucleotide, abbreviated NAD, is a coenzyme found in all living cells. The compound is a dinucleotide, since it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine base and the other nicotinamide.In metabolism, NAD is involved...
  
   + H₂O
• Vulgaxanthin-I + H₂O = Vulgaxanthin-II + Ammonia
• Vulgaxanthin-II + ATP
  Adenosine triphosphate
  Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
  
   + Ammonia = Vulgaxanthin-I + ADP
  Adenosine diphosphate
  Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
  
   + Orthophosphate
• Vulgaxanthin-II + ATP + Ammonia = Vulgaxanthin-I + Diphosphate + 5'-AMP
• Betalamic acid + L-Glutamine + ATP = Vulgaxanthin-I + ADP + Orthophosphate