Rate and equilibrium constants for the dehydration and deprotonation reactions of some monoacylated and glycosylated cyanidin derivatives
The rate and equilibrium constants for the pH-dependent hydration of a series of monoacylated anthocyanins semi-biosynthesized using a wild carrot suspension culture have been measured. The features of the acyl groups that decrease the hydration and thus decrease the loss of color of these anthocyanins are the presence of the side-chain double bond of the cinnamic acids and the presence of electron-donating substituents at the para-position of the acyl group. Methoxyl groups in the meta-position of the acyl groups have a greater effect than can be explained by their effects on the electron density in the acyl group. The data also suggest that there may be additional features of the acyl groups which contribute to the color retention in anthocyanins.
Redus, Marc,Baker, David C.,Dougall, Donald K.
p. 3449 - 3454
(2007/10/03)
Anthocyanins from wild carrot suspension cultures acylated with supplied carboxylic acids
The anthocyanins accumulated by carrot cell cultures include some that are acylated. Addition of cinnamic and benzoic acid analogues to the culture medium resulted in the production of fourteen novel monoacylated anthocyanins. Four additional anthocyanins were prepared by partial acid hydrolysis, which selectively removed the xylose side chain from the branched trisaccharide part of the molecule. The carrot cells accommodate a wide range of carboxylic acids used to acylate anthocyanins and provide a system for the preparation of anthocyanins that have a variety of acyl groups attached. The compounds were characterized by 1H NMR spectroscopy and mass spectrometry, and by UV-vis absorption spectroscopy at both pH 2 and 6. Copyright (C) 1998 Elsevier Science Ltd.
Dougall, Donald K.,Baker, David C.,Gakh, Elena G.,Redus, Marc A.,Whittemore, Neil A.
p. 177 - 189
(2007/10/03)
More Articles about upstream products of 142506-19-2