Chemical and Antioxidant Properties of Betalains

Abstract

Betalains are vacuolar pigments composed of a nitrogenous core structure, betalamic acid. Betalamic acid condenses with imino compounds (cyclo-DOPA/its glucosyl derivates) or amino acids/derivates to form violet betacyanins and yellow betaxanthins. These pigments have gained the curiosity of scientific researchers in recent decades. Their importance was increased not only by market orientation toward natural colorants and antioxidants but also by their safety and health promoting properties. To date, about 78 betalains have been identified from plants of about 17 families. In this review, all of the identified pigments are presented, followed by a comprehensive discussion of their structure–activity relationship.

LC-MS Analysis of Phenolic Acids, Flavonoids and Betanin from Spineless <i>Opuntia ficus-indica</i> Fruits

“…This fragment ion was produced by fragmentation of the parent ion of m/z of 551 assigned to betanin and indicated that it corresponds to the protonated aglycone betanidin obtained by glucose loss. Our results are in accordance with those reported by Belhadj Slimen et al [9] and Nestora et al [15]. …”

“…Numerous phytochemicals were identified: phenolic acids, flavonoids, betalains, ascorbic acid, carotenoids and tocopherols. Indeed, prickly pears contain considerable amounts of vitamins, amino acids, sterols, fatty acids, sugars and minerals [8,9]. This paper aims to identify and quantify phenolic acids, flavonoids and betalains from Tunisian spineless Opuntia ficus-indica fruits.…”

Opuntia ficus‐indica (L.) Mill. fruit as source of betalains with antioxidant, cytoprotective, and anti‐angiogenic properties

“…Therefore, it is possible to postulate that the greater antioxidant and free radical scavenging power of betacyanins in cell‐free based assay, characterized by hydrophilic and buffered environments, is attributable to the greater hydrophilicity of these molecules, as well as to the greater ability to establish hydrogen bonds with respect to the betaxantins. Furthermore, the betalains antiradical activity is pH‐dependent; betanin, indeed, exhibits the highest radical scavenging activity at pH > 4 (Belhadj Slimen et al, ).…”

“…The radical quenching activity is due to the presence of a catechol structure as well as to the imino and tetrahydropyridine groups, which stabilizes the system for resonance lead to the formation of a stable carbocation upon an electron abstraction. This may explain the electron donator properties of betalains and consequently their reducing ability (Belhadj Slimen et al, ).…”

“…However, the extent of glycosylation decreases the antioxidant activity, whereas acylation increases the activity (Belhadj Slimen et al, ).…”