Delphinidin-3-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... 

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). 

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