A simple synthesis of 3-deoxyanthocyanidins and their O-glucosides

Abstract

This work deals with the chemical synthesis of simple analogs of anthocyanins, the main class of watersoluble natural pigments. Flavylium ions with hydroxyl, methoxyl and b-D-glucopyranosyloxyl substituents at positions 4 0 and 7 have been prepared by straightforward chemical procedures. Moreover, the two 3-deoxyanthocyanidins of red sorghum apigeninidin (4 0 ,5,7-trihydroxyflavylium) and luteolinidin (3 0 ,4 0 ,5,7-tetrahydroxyflavylium) were synthesized in a one-step protocol. Attempts to synthesize luteolinidin O-b-D-glucosides resulted in a mixture of the 5-O-and 7-O-regioisomers in low yield. A preliminary study of the 4 0-b-D-glucopyranosyloxy-7-hydroxyflavylium and 7-b-D-glucopyranosyloxy-4 0hydroxy-flavylium ions shows that simply changing the glucosidation site can profoundly affect the color intensity and stability.

Binding of the five multistate species of the anthocyanin analog 7-β-D-glucopyranosyloxy-4′-hydroxyflavylium to the β-cyclodextrin derivative captisol

“…All solutions were prepared in Millipore water. 0.2 mM GHF [19] and 0.2 M captisol stock solutions were prepared using 0.1 M HCl and water, respectively. Any pH adjustment was achieved by addition of HCl, NaOH or Theorell and Stenhagen's universal buffer, pH was recorded on a Radiometer Copenhagen PHM240 pH/ion meter (Brønshøj, Denmark).…”

Analogs of Natural 3-Deoxyanthocyanins: O-Glucosides of the 4′,7-Dihydroxyflavylium Ion and the Deep Influence of Glycosidation on Color

“…All pigments were chemically synthesized according to already published procedures and completely characterized by NMR and HPLC-DAD-MS analysis [16]. …”

Progress and Achievements in Glycosylation of Flavonoids

“…As an example of an "acidic" version of the synthesis, which provides for the glycosylation of the starting products and the subsequent assembly of flavonoid glycosides, one can mention the work ( Al Bittar et al, 2016 ). The authors obtained various anthocyanidin glycosides based on 2,4-dihydroxybenzaldehyde (1) and 3,4-dihydroxy-acetophenone (4) ( Figure 1A ).…”