Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: betanidyna

Sortuj według:

Ogranicz wyniki do:

Semi-synthesis of red beet betacyanin ethyl-esters by esterification

Tuwalska D., Starzak K., Szot D., Wybraniec S., Winterhalter P., Jerz G.

Challenges of Modern Technology

2014

Vol. 5, no. 3

27--31

Red beet pigments recovered from Beta vulgaris L. (Chenopodiaceae), mainly consist of purple betacyanins, such as 15R/15S-betanin. Currently,this pigment class is intensively investigated in respect of stability in food systems. Quite popular is the use of red beet extracts in dairy products such as yoghurts, and ice-creams. So far, there are no issues of toxicity using these natural pigments in food – so they seem to be a very good alternative to replace synthetic dyes which had been frequently discussed for negative side-effects to human health. Betacyanins, the glycosidation products of betanidin are very polar and therefore water soluble pigments, which are biosynthetically derived from condensation of cyclo-DOPA and betalamic acid. The significant polarity of betacyanins requires the use of ion-pair reagents such as trifluoro-acetic acid (TFA) or other homologue fluorinated additives under standard separation conditions on larger scale in spiral coil countercurrent chromatography (spCCC). In our synthetic experiment, the polarity of the natural betacyanins was reduced. This omitted the use of toxic per-fluoro ion-pair reagents. The three carboxylic groups of the betanin pigment backbone were the target functional groups of the derivatisation. In semi-synthesis, fortified red beet pigment extract was esterified with water-free ethanolic hydrogen chloride solution. The reaction was carried out at ambient temperature (7 days) to yield a mixture of betacyanin mono-, di- and tri-ethyl-esters, and their epimeric forms, as well as the respective betanidin-ethyl-esters. The time course of the reaction mixture was monitored by analytical C18-HPLC with ESI-DAD-MS/MS detection. The detected molecular weights of the pigments confirmed the presence of expected products. To the best of our knowledge, the presence of betalains containing ethyl-ester groups in biological samples have not been studied before.

Stability of Betanidin Influenced by Copper Cations

Tuwalska D., Starzak K., Szot D., Skopińska A., Wybraniec S.

Logistyka

2013

nr 4

Latest studies revealed some antioxidant properties of betalain pigments that contribute to the growth of interest in these compounds. During the isolation and storage, betalains are exposed to many different chemical and physical degradative factors, which often lead to their decomposition and discoloration. An effect of copper cations on betanidin stability was investigated in aqueous and organic-aqueous solutions. Betanidin stability experiments were performed at different pH’s, with different concentrations of metal cations and in different solvents. Using the modern spectrophotometric microplate reader it was possible to monitor changes of absorption spectra of the pigment samples during their incubation with copper ions in parallel at various physico-chemical conditions. Incubation with copper cations leads to betanidin degradation in all investigated solvents in the whole range of pH. The formed products are its new oxidized derivatives. A possibility of a formation of metal-pigment complexes is also considered. Recognition of betalains degradation paths is important because of their not yet fully recognized antioxidant and chemopreventive properties.

Ostatnie badania wykazały przeciwutleniające właściwości betalain, co przyczyniło się do wzrostu zainteresowania tą grupą związków. Podczas izolacji i przechowywania, betalainy są narażone na wiele różnych degradujących czynników, chemicznych i fizycznych, które często powodują ich rozkład i odbarwienie. Zbadano wpływ kationów miedzi na stabilność betanidyny w roztworach wodnych i wodno-organicznych. Eksperymenty były przeprowadzane w różnym pH, z różnymi stężeniami kationów metalu i rozpuszczalników organicznych. Zastosowanie nowoczesnego spektrofotometrycznego czytnika mikropłytek pozwoliło na monitorowanie zmian w widmie absorpcyjnym pigmentu w różnych warunkach fizyko-chemicznych. Inkubacja betanidyny z jonami miedzi prowadzi do jej degradacji we wszystkich badanych rozpuszczalnikach w całym zakresie pH. Powstałe produkty są jej nowymi, utlenionymi pochodnymi. Rozważano również powstawanie kompleksu metal-pigment.Poznanie szlaków utleniania betalain jest ważne z powodu nie w pełni jeszcze poznanych ich antyutleniających i chemoprewencyjnych właściwości.