Betanidins

The study of these fragments, coupled with the results of additional research (139), estabUshed the stmcture of betanin [7659-95-2] (50). Betanidin [37279-84-8] was synthesized in 1975 (140). A small amount of two yellow pigments is present also in beets (51). These have no value as food dyes. 

C7H()N 100-46-9) see Amosulalol Bamidipine Beclamide Benperidol Betanidine Biotin Cisapride Dilevalol Guanoxan Moxifloxacin hydrochloride NebivOlol Nialamide Reproterol Sparfloxacin Sulbentine Viloxazine benzylamine hydrochloride (C7H,()C1N 3287-99-8) see Benzyl mustard oil 2-benzylaminoethanol... 

CjH NS 556-61-6) see Betanidine Thiamazole 5-methylisothiosemicarbazide hydriodide (CjHnINjS 35600-34-1) see Guanoxabenz 5-methylisothiourea... 

Turner speculated that the two families arose from a common ancestor that likely occupied xeric or halophytic habitats in Gondwana in an area that encompassed what were to become southwestern Africa and southeastern South America. The ancestral types do not still exist, but both families share the unusual, betanidin-based floral chemistry, and the equally unique sieve-tube plastids seen in Caryophyllales but are absent elsewhere in the plant kingdom (Behnke and Turner, 1971). 

Wyler, H., Mabry, T.J., and Dreiding, A.S., Zur Struktur des Betanidins tJber die Konstitution des Randenfarbstoffes Betanin, Helv. Chim. Acta, 46, 1745, 1963. 

Vogt, T., Substrate specificity and sequence analysis define a polyphyletic origin of betanidin 5- and 6-0-glucosyltransferase from Dorotheanthus bellidiformis, Planta, 214, 492, 2002. 

As for anthocyanins, betalains are found in vacuoles and cytosols of plant cells. From the various natural sources of betalains, beetroot (Beta vulgaris) and prickly pear cactus (Opuntia ficus indica) are the only edible sources of these compounds. In the food industry, betalains are less commonly used as natural colorants from plant sources than anthocyanins and carotenoids, probably related to their more restricted distribution in nature. To date, red beetroot is the only betalain source exploited for use as a natural food coloring agent. The major betalain in red beetroot is betanin (or betanidin 5-0-P-glucoside). Prickly pear fruits contain mainly (purple-red) betanin and (yellow-orange) indicaxanthin and the color of these fruits is directly related to the betanin-to-indicaxanthin ratio (99 to 1, 1 to 8, and 2 to 1, respectively in white, yellow, and red fruits)." ... 

Betalains are N-heterocyclic water-soluble pigments deposited in vacuoles. Their common precursor is betalamic acid consisting of a 1,7-diazaheptamethin system, an extended Jt-electron system exhibiting a canary yellow color. Betalamic acid may condense with cyc/o-dopa to yield betanidin, the common precursor aglycon of the red betacyanins. Betanidin in turn may be glycosylated and/or acylated, yielding 29... 

FIGURE 13.7 Structures for the representative betalains vulgaxanthin I (betaxanthin) and betanidin (betacyanin). 

Gandia-Herrero F, Escribano J and Garcia-Carmona F. 2007. Characterization of the activity of tyrosinase on betanidin. J Agric Food Chem 55(4) 1546-1551. 

Bougainvillea brasiliensis Raeusch B. glabra Choisy var. sanderiana Hort. Jiu Chung (flower, stem) Betanidin, isobeturudin, 6-O-P-sophoraside, 6-O-rhamnosyl cophoroside.54 Treat liver infection, regulate menses. 

Portulaca grandiflora Hooker Song Ye Mo (Purslane) (whole plant) Portulal, betacyanin, betanin, betanidin.55 Treat throat swelling and pain, externally for bums, wounds and infections. 

The aglycone of betaniu, the red-violet pigment of the beet (Beta vulgaris var. rubra), known as betanidin, has recently been shown to have the structure depicted in structural formula 113.170,282 Betanidin had previously been reported by Piattelli and Minale to contain a dopachrome unit in its structure and consequently would have been formulated as 114.109 The Italian workers obtained pyrrole-2,3,5-tricarboxylic acid and pyridine-2,4,6-tricarboxylic acid on permanganate oxidation of betanidin and they also prepared a semi-carbazone of the pigment, the absorption spectrum of which showed the pH dependency expected for an aminochrome semicarbazone.169... 

Wyler et al., however, believe that the aminochrome monosemicar-bazone obtained by Piattelli and Minale was in fact dopachrome monosemicar bazone, formed after decomposition of the betanidin molecule, which occurs readily in air.170,282... 

Figure F3.1.1 Isocratic gradient LC chromatogram of betacyanin pigments. Peak A betanin peak B isobetanin peak C betanidin, and peak D isobetanidin. Adopted from Schwartz and von Elbe (1980).

The high-performance liquid chromatography method (see Basic Protocol 2) allows for the separation of individual betanin and its aglycon betanidin and their isomers. The agly-con is naturally occurring in beet tissue, but in relatively small amounts. The isomers, isobe-tanidin and isobetanin, are easily formed when solutions of beet extract are subjected to either heat or acid (Schwartz and von Elbe, 1983). The... 

Currently over 50 betacyanins have been identified, but most of them are based on the two isomeric aglycones betanidin and isobetanidin (the C15 epimer of betanidin), whose chemical structures are shown in Fig. 19. According to the formula for betanidin, there are two asymmet-... 

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