Vulgaxanthin

Vulgaxanthins are a group of betaxanthins, or the predominant yellow plant pigments found in red beets, among other plants like Mirabilis jalapa and swiss chard. They are antioxidant pigments, types I, II, III, IV, and V. Like all betaxanthins, they cannot be hydrolyzed by acid to aglycone without degradation. Water activity also affects stability of this antioxidant. It has been studied as a natural nutritional additive but instability remains a problem.

Reactions

 * Vulgaxanthin-II + Ammonia + NADH = Vulgaxanthin-I + NAD+ + H2O
 * Vulgaxanthin-I + H2O = Vulgaxanthin-II + Ammonia
 * Vulgaxanthin-II + ATP + Ammonia = Vulgaxanthin-I + ADP + Orthophosphate
 * Vulgaxanthin-II + ATP + Ammonia = Vulgaxanthin-I + Diphosphate + 5'-AMP
 * Betalamic acid + L-Glutamine + ATP = Vulgaxanthin-I + ADP + Orthophosphate