Malvidin monoglucoside

Rivas-Gonzalo, J.C., Bravo-Haro, S., and Santos-Buelga, C., Detection of compounds formed through the reaction of malvidin-3-monoglucoside in the presence of acetaldehyde. J. Agric. Food Chem. 43, 1444, 1995. 

Experimentally, Sondheimer (14) for pelargonidin-3-monoglucoside and Berg (15) for malvidin-3-monoglucoside found the values of pK to be close to 3 which is close to the pH of wine. At this pH about 50% of the anthocyanin molecules are in the red form and 50% are in the colorless form. 

Francia-Aricha, E.M., Rivas-Gonzalo, J.C. Santos-Buelga, C. (1998). Effect of malvidin-3-monoglucoside on the hrowning of monomeric and dimeric flavanols. Zeitschrift fur Lebensmittel-Untersuchung und-ForschungA, 207, 223-228. 

The following values were calculated by Brouillard et al. (1978) for malvidin monoglucoside... 

There are five anthocyanidins in the grape delphinidin 1, petunidin 2, malvidin 3, cyanidin 4, and peonidin 5. These aglycones exist in different heterosidic forms or as anthocyanins 3-monoglucosides, 3,5-diglucosides, and acylated heterosides, whose structures, in the case of malvidin, are represented by formulas 6, 7, and 8. In the acylated anthocyanins, one molecule of cinnamic acid, more generally p-coumaric acid, is esterified with the —OH group in the sixth position of a glucose molecule (12). 

Two series of ions are evident, representing monoglucosides (1-5) and acetylglucosides (6-10) of the following aglycones cyanidin (1, 6 1.40), peonidin (2, 7 1.41), delphinidin (3, 8 1.42), petunidin (4, 9 1.43) and malvidin (5, 10 1.44). These results were obtained with a first-generation (continuous mode) MALDI mass spectrometer that did not have delayed... 

Anthocyanidins (aglycones), flavyliun salts (chlorides), are shown generally by (1), the anthocyanins (3-monoglucosides) by (2), and 3,5-diglucosides by (3). The major anthocyanidins are cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin and the substituents in their structures are shown below for the formula (1). Table 3... 

Analysis by the uv absorption of citrate buffered solutions enables the I anthocyanin to be determined from the maximum at 520nm. The distribution of component anthocyanins can be found by TLC on cellulose with various strongly acidic solvents (eg. cone HCl, formic acid, water, 19 19.5 61.5) of extracts of plant material obtained with 1% hydrochloric acid in methanol. The Rf values found for 3-monoglucosides of the anthocyaninidins of Vitis vinifera were, for the petunidin compound (0.13), for that of malvidin (0.22) and of peonidin (0.25) (ref. 11). ... 

Compments. The primary anthocyanins of V. vinifera grapes appear to be the monoglucoside oenin and some diglucoside. Levy el al. (1931) found a small amount of delphinidin and its 3 -methyl ester in the Fogarina (i.e., Fogaruna ) grape. The absorption curve of natural and synthetic oenin chloride (malvidin) from 420 m. to 600 m/i. and the distribution numbers in a special solvent were identical for the synthetic and natural product. The picrate consisted of only about 45% oenin— the remainder may be petunidin (delphinidin 3 -methyl ester) and delphinidin. 

Anthocyanins are the most abundant pigments in red grape skins (Fig. 83.2a). These water-soluble pigments are responsible for blue, red, and purple color in red grape skin and red wine. Anthocyanins of Vitis are monoglucosides of five anthocyanidins, namely, delphinidin, cyanidin, petunidin, peonidin, and malvidin. Acylated anthocyanins are esters of the glucose moiety of the free anthocyanins with acetic, p-coumaric, or caffeic acids (Fig. 83.2a). 

---