Biogenesis of betalamic acid

Chang, Christina; Kimler, Linda; Mabry, Tom J.

doi:10.1016/0031-9422(74)80240-2

Cited by 21 publications

(7 citation statements)

References 9 publications

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“…fresh extracts or juices, purified samples), the quantitation of betalains can be accomplished using spectrophotometry, whereby absorbance at the visible maximum is expressed in terms of concentration by use of appropriate absorptivities [449,502,516,[524][525][526]. Nilsson [527] developed a spectrophotometric method that directly determines betacyanin and betaxanthin pigments in beets without their initial separation.…”

Section: Quantitative Analysismentioning

confidence: 99%

“…The dihydropyridine moiety present in all betalains is synthesized in vivo from two molecules of L-5,6-dihydroxyphenylalanine (L-DOPA), one of which must first undergo 4,5-extradiol oxidative cleavage and recyclization [448] through seco-DOPA [449,450] to betalamic acid (Figure 8.9). Alternatively, in toadstools L-DOPA undergoes 2,3-extradiol cleavage to form muscaflavin [6].…”

Section: Biosynthesismentioning

confidence: 99%

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Natural Food Colorants

1996

109

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Preface to the second editionIn this second edition of Natural Food Colorants two new chapters have been added and we have taken the opportunity to revise all the other chapters. Each of the original authors have brought up to date their individual contributions, involving in several cases an expansion to the text by the addition of new material. The new chapters are on the role of biotechnology in food colorant production and on safety in natural colorants, two areas which have undergone considerable change and development in the past five years. We have also persuaded the publishers to indulge in a display of colours by including illustrations of the majority of pigments of importance to the food industry. Finally we have rearranged the order of the chapters to reflect a more logical sequence. We hope this new edition will be greeted as enthusiastically as the first.It remains for us, as editors, to thank our contributors for undertaking the revisions with such thoroughness and to thank Blackie A&P for their support and considerable patience.

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Section: Quantitative Analysismentioning

confidence: 99%

Section: Biosynthesismentioning

confidence: 99%

Natural Food Colorants

1996

109

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“…1). In early studies, this transformation was demonstrated in betalain-producing fungi and plants with radiolabeled precursors tyrosine and DOPA (Fischer and Dreiding 1972;Chang et al 1974). The first attempts at purifying the enzyme demonstrated the existence of a betalamic acid formation activity in the fungus Amanita muscaria (Girod and Zryd 1991).…”

Section: Introductionmentioning

confidence: 99%

Characterization of recombinant Beta vulgaris 4,5-DOPA-extradiol-dioxygenase active in the biosynthesis of betalains

García-Carmona

2012

Planta

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Betalains are water-soluble pigments with high antiradical capacity which bestow bright colors to flowers, fruits and other parts of most plants of the order Caryophyllales. The formation of the structural unit of all betalains, betalamic acid from the precursor amino acid 4,5-dihydroxyphenylalanine is catalyzed by the enzyme 4,5-DOPA-extradiol-dioxygenase followed by intramolecular cyclization of the 4,5-secodopa intermediate. This paper describes the purification and the molecular and functional characterization of an active 4,5-DOPA-extradiol-dioxygenase from the best-known source of betalains-Beta vulgaris-after heterologous expression in Escherichia coli. The enzyme is a monomeric protein with a molecular mass of 32 kDa characterized by chromatography, electrophoresis and MALDI-TOF analysis. Enzyme kinetic properties are characterized in the production of betalamic acid, the structural, chromophoric and bioactive unit of plant pigment betalains.

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“…In the proposed pathway for betalamic acid biosynthesis, the amino acid (S)-Tyr is the precursor, and it is oxidized by tyrosinase to produce (S)-DOPA, which is then the substrate for a specific dioxygenase. This enzyme is able to cleave the aromatic ring to obtain the 4,5-seco-DOPA intermediate that spontaneously experiences an intramolecular condensation leading to attainment of betalamic acid (Chang et al, 1974). The enzyme 4,5-dioxygenase has been partially characterized in Amanita muscaria (Girod and Zrÿ d, 1991) and recently in Portulaca grandiflora (Christinet et al, 2004).…”

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confidence: 99%

Betaxanthins as Substrates for Tyrosinase. An Approach to the Role of Tyrosinase in the Biosynthetic Pathway of Betalains

Escribano

García-Carmona

2005

Plant Physiology

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Tyrosinase or polyphenol oxidase (EC 1.14.18.1) is the key enzyme in melanin biosynthesis and in the enzymatic browning of fruits and vegetables. The role of tyrosinase in the secondary metabolism of plants still remains unclear, but its implication in betalain biosynthesis has been proposed. Betalains are an important class of water-soluble pigments, characteristic of plants belonging to the order Caryophyllales. In this article, the betaxanthins, tyrosine-betaxanthin (portulacaxanthin II) and dopaxanthin, are reported to be physiological substrates for tyrosinase. The direct activity of tyrosinase on selected betaxanthins is characterized in depth, and conversion of tyrosine-betaxanthin to dopaxanthin and its further oxidation to a series of compounds are described. Identity of the reaction products was studied by high-performance liquid chromatography and electrospray ionization-mass spectrometry. Masses determined for the reaction products were the same in all cases, 389 m/z ([M 1 H] 1 ) and equal to that determined for betanidin. Data indicate that dopaxanthin-quinone is obtained and evolves to more stable species by intramolecular cyclization. Kinetic parameters for tyrosinase acting on dopaxanthin were evaluated, showing a high affinity for this substrate (K m 5 84.3 mM). The biosynthetic scheme of betalains is reviewed and a branch is proposed based on the description of physiological substrates for tyrosinase. Lampranthus productus, Glottiphylum oligocarpum, and Glottiphylum pigmaeum are described as sources of stereopure (2S/S)-dopaxanthin.Tyrosinase or polyphenol oxidase (monophenol, o-diphenol:oxygen oxidoreductase; EC 1.14.18.1) is a copper enzyme that catalyzes two different reactions using molecular oxygen: the hydroxylation of monophenols to o-diphenols (monophenolase activity) and the oxidation of the o-diphenols to o-quinones (diphenolase activity; Sánchez-Ferrer et al., 1995). This enzyme is widely distributed in plants, microorganisms, and animals where tyrosinase is responsible for melanization.A wide variety of plant tyrosinase behaviors has been described and reviewed (Mayer and Harel, 1991;van Gelder et al., 1997). A molecular oxygenscavenging function in the chloroplast (Vaughn et al., 1988) and a role in plant defense (Constabel et al., 1995) have been suggested. Its implication in the secondary metabolism of betalains has been proposed (Steiner et al., 1999), but the physiological function of tyrosinase in higher plants is yet to be fully determined.Betalains are water-soluble nitrogen-containing pigments that are present in plants belonging to the order Caryophyllales (Strack et al., 2003) and in the fungal genera Amanita (Musso, 1979) and Hygrocybe (von Ardenne et al., 1974). All betalain pigments contain betalamic acid as the chromophore. Depending upon the nature of the betalamic acid addition residue, the betalains can be classified as either betacyanins or betaxanthins. Betacyanins contain a cyclo-3,4-dihydroxyphenylalanine (cyclo-DOPA; usually glycosylated) residue and exhibit ...

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Biogenesis of betalamic acid

Cited by 21 publications

References 9 publications

Natural Food Colorants

Natural Food Colorants

Characterization of recombinant Beta vulgaris 4,5-DOPA-extradiol-dioxygenase active in the biosynthesis of betalains

Betaxanthins as Substrates for Tyrosinase. An Approach to the Role of Tyrosinase in the Biosynthetic Pathway of Betalains

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