کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5272410 1385463 2013 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Network of carboxypyranomalvidin-3-O-glucoside (vitisin A) equilibrium forms in aqueous solution
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Network of carboxypyranomalvidin-3-O-glucoside (vitisin A) equilibrium forms in aqueous solution
چکیده انگلیسی

The equilibrium forms of carboxypyranomalvidin-3-O-glucoside (vitisin A) were studied in aqueous solution at different pH values by NMR and UV-Visible spectroscopy. The results obtained revealed the presence of three deprotonation reactions at positions 10-COOH, 7-OH and 4′-OH: pKa1 = 1.09 ± 0.09; pKa2 = 4.93 ± 0.02; pKa3 = 9.14 ± 0.05, data obtained from NMR titration. The titration by NMR confirmed the absence of hydration reactions since no characteristic peaks of the hemiketal form were observed in the NMR spectrum at any pD value studied (pD 0.67-10.99).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron Letters - Volume 54, Issue 37, 11 September 2013, Pages 5106-5110
نویسندگان
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