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    Wyświetlanie 1-4 z 4
    Tytuł:
    Profiles of products generated during betacyanins reduction by 2-methylpyridine borane
    Autorzy:
    Szot, D.
    Starzak, K.
    Skopińska, A.
    Wybraniec, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/115550.pdf
    Data publikacji:
    2015
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betanina
    neobetanina
    betacyjaniny
    redukcja
    2-2-metylopirydyna boranu
    LC-MS
    betanin
    neobetanin
    betacyanins
    reduction
    2-methylpyridine borane
    Opis:
    Betanin and neobetanin (14,15-dehydrogenated betanin), natural betacyanin pigments were subjected to a gentle reduction by 2-methylpyridine borane. During each reduction reaction, the visible spectra were collected. The results were tentatively confirmed by LC-DAD-ESI-MS. In comparison to a previous study with sodium borohydride, various types of products were obtained. Depending on pH, one or two double bonds are reduced. Interestingly, a preliminary decarboxylation of the pigments is also noticed. Betacyanins are plant red-violet pigments applied as colorants in food and pharmaceutical industry which are proven to have an antioxidant activity. They are confirmed to be beneficial for human health as free radical scavengers. Therefore, betacyanins can prevent from many diseases which would be induced by an excessive accumulation of free radicals in the human body. There are more and more reports of their pro-health properties. However, the mechanism of betacyanins oxidation remains not completely elucidated. It is postulated that the rearrangement in the chromophoric system is a significant part of this mechanism. The products obtained as a result of reduction of betanin and neobetanin can be useful in oxidation investigations. Betacyanins with partially destroyed chromophoric system by reduction of the double bonds would by perfect models for further studies on their oxidation.
    Źródło:
    Challenges of Modern Technology; 2015, 6, 4; 19-22
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Reactions of decarboxylated betanins under influence of halogen light
    Autorzy:
    Skopinska, A.
    Szot, D.
    Starzak, K.
    Wybraniec, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/115710.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betanin
    decarboxylated betacyanins
    photolability
    mass spectrometry
    betanina
    dekarboksylacja betacyjaniny
    spektrometria masowa
    Opis:
    Betalains as natural plant pigments are very sensitive to several factors, including light, therefore, studies on stability of their derivatives which retain their attractive color, are crucial for their potential application in pharmaceutical, food or cosmetic industries. An effect of irradiation by halogen light on reactivity of main decarboxylated derivatives of betacyanins (2-decarboxy-betanin, 17-decarboxy-betanin and 2,17-decarboxy-betanin) was investigated in aqueous and organic-aqueous solutions: 50% (v/v) acetonitrile, 50% (v/v) methanol and 50% (v/v) ethanol, at pH range 3-8. The double decarboxylation of betanin (at C-2 and C-17 position of carbon) significantly increases the stability of this pigment in the acidic media. As a result of pigments reactions induced by light, some betacyanin derivatives with different decarboxylation and dehydrogenation levels were identified by chromatography with tandem mass spectrometry (LC-MS/MS) and diode array detection (LC-DAD).
    Źródło:
    Challenges of Modern Technology; 2014, 5, 3; 37-43
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Semi-synthesis of red beet betacyanin ethyl-esters by esterification
    Autorzy:
    Tuwalska, D.
    Starzak, K.
    Szot, D.
    Wybraniec, S.
    Winterhalter, P.
    Jerz, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/115735.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betacyanin ethyl-esters
    betalains
    betacyanins
    betanin
    betanidin
    esterification
    estry etylowe
    betalainy
    betacyjaniny
    betanina
    betanidyna
    estryfikacja
    Opis:
    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.
    Źródło:
    Challenges of Modern Technology; 2014, 5, 3; 27-31
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of citric acid on stabilization of betanin solutions
    Autorzy:
    Skopińska, A.
    Szot, D.
    Tuwalska, D.
    Starzak, K.
    Osiadło, M.
    Wybraniec, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/115716.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betanin
    betacyanins
    citric acid
    Beta vulgaris L.
    betanina
    betacyjaniny
    kwas cytrynowy
    Opis:
    Elevated temperature is known to be the most crucial factor influencing betanin integrity during food processing and storage. Nevertheless, certain chelating agents or antioxidants, such as acetic acid, may act as stabilizers. Therefore, the effect of citric acid on the stability of betanin – basic betacyanin – was investigated during the heating experiments in water as well as 50% and 95% (v/v) aqueous-organic solutions of methanol, ethanol and acetonitrile. The presence of citric acid in tested solutions affects betanin stability, especially in the 95 % solutions, in which the stabilizing effect of this compound is significantly higher than in aqueous solutions. However, some decrease of retention in 50% methanol was also observed. The main products of betanin thermal degradation in aqueous and aqueous-organic solutions were compounds characterized by absorption bands around the wavelength at 420 nm.
    Źródło:
    Challenges of Modern Technology; 2014, 5, 2; 19-24
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-4 z 4

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