Mixtures of mono-, bi-, and tridecarboxylated betacyanins together with their corresponding neobetacyanins obtained from Beta vulgaris L. root juice as heating degradation products of betacyanins were identified by high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) and diode-array (LC-DAD) detection. Two monodecarboxy-betacyanin pairs of diastereomers were detected after the decarboxylation in ethanolic and aqueous solutions. Generation of 17-decarboxy-betacyanins and 2-decarboxy-betacyanins was suggested, the latter so far never having been attributed to betacyanin thermal degradation products. Other main products of decarboxylation were 2,17-bidecarboxybetanin, its isoform, and 14,15-dehydrogenated (neobetacyanin) derivatives of all the decarboxylated betacyanins. The results of this research are crucial in determining betacyanin degradation mechanisms in juices or extracts of B. vulgaris L. roots and other products containing these pigments.

Formation of Decarboxylated Betacyanins in Heated Purified Betacyanin Fractions from Red Beet Root (Beta vulgaris L.) Monitored by LC-MS/MS

The pigments of fly agaric, Amanita muscaria

Pigments of purple pitaya [Hylocereus polyrhizus (F.A.C. Weber) Britton and Rose] fruits were submitted to extraction and were decarboxylated during heating experiments in acidified ethanolic and aqueous solutions. Groups of betacyanins with different decarboxylation levels were identified in the heating products by LC-DAD and LC-MS/MS. The main decarboxylation products were 2-decarboxy-betacyanins, 17-decarboxy-betacyanins, and 2,17-bidecarboxy-betacyanins. The structures of other compounds were assigned to 2,15,17-tridecarboxy-betacyanins and 14,15-dehydrogenated derivatives (neo-derivatives) of all decarboxylated betacyanins found.

Generation of decarboxylated and dehydrogenated betacyanins in thermally treated purified fruit extract from purple pitaya (Hylocereus polyrhizus) monitored by LC-MS/MS.

Formation and occurrence of dopamine-derived betacyanins

Betanidin is a basic betacyanin with a 5,6-dihydroxyl moiety which causes its high antioxidant activity. For the purpose of structural study, the enzymatic oxidation of betanidin and betanin (5-O-glucosylated betanidin), followed by chromatographic separation of the oxidation products with spectrophotometric and mass spectrometric detection (LC-DAD-MS/MS) was performed. Within the pH 4-8 range, two main oxidation peaks of betanidin were observed, betanidin quinonoid (possibly betanidin o-quinone) and 2-decarboxy-2,3-dehydrobetanidin, whereas at pH 3 only dehydrogenated and decarboxylated derivatives were detected, suggesting different stabilities of the products at different pH values. The presence of two prominent oxidation products, 2-decarboxy-2,3-dehydrobetanidin and 2,17-bidecarboxy-2,3-dehydrobetanidin, at pH 3 indicates their generation via two possible reaction routes with two different quinonoid intermediates: dopachrome derivative and quinone methide. Both reaction paths lead to the decarboxylative dehydrogenation of betanidin. Subsequent oxidation and rearrangement of the conjugated chromophoric system results in the formation of 14,15-dehydrogenated derivatives. Betanin is oxidized with generation of a quinone methide intermediate, which rearranges to 2,3-dehydro- or neoderivatives. The products of enzymatic oxidation of betacyanins thus formed are derivatives of 5,6-dihydroxyindole and related structures known as the key intermediates in melanogenesis.

New pathways of betanidin and betanin enzymatic oxidation.

Bei der Biogenese des Betanins (2) aus Dopa (1) wird die Carboxylgruppe der Aminosaure in die Carboxylgruppe-C(19) umgewandelt. Dieser Schluss beruht auf einem Deuterierungsversuch, bei dem gezeigt wird, dass die Monodecarboxylierung von Betanidin (3) zu einem Verlust von C(19) fuhrt und dass dabei die Doppelbindung C(17)C(18) nach C(14)C(15) wandert. Wenn radioaktives Betanidin (3), erhalten aus Einbauexperimenten mit DL-Dopa-[1-14C], in Athanol decarboxyliert wird, erhalt der danach isolierte Dimethylester 7 des Decarboxybetanidin (6)-hydrochlorids nur noch 14% des 14C.



Bei der alkali-katalysierten Aquilibrierung von Betanidin (3) ⇆ Isobetanidin (9) tritt im Gegensatz zur Decarboxylierung keine Wanderung der Doppelbindung ein.

On the mechanism of decarboxylation of betanidine. A contribution to the interpretation of the biosynthesis of betalaines.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

H. E. Miller

Author Tools

Chat about Author

Papers

On the mechanism of decarboxylation of betanidine. A contribution to the interpretation of the biosynthesis of betalaines.