Anthocyanidins malvidin

Piovan et al. [80] reported the characterization of anthocyanins in both flower material and in vitro cnltmes of Catharanthus roseus. The anthocyanidins malvidin, petunidin, and hirsntidin were identified from both sonrces. Next to known aglycones, three 3-0-glycosides as well as three 3-0-(6-0-/)-coumaroyl)glycosides... 

Six anthocyanidins are commonly found in plants and plant-derived foods and beverages pelargonidin, cyanidin, delphinidin, peonidin, petunidin, and malvidin. Their structures differ in the number and position of hydroxyl and methoxyl groups on the flavan nucleus. The most commonly occurring anthocyanidin is cyanidin, and all these anthocyanidins are found in plants as glycosides with or without acylation, leading to around 400 different stractures. 

Malvidin was detected in amounts greater than 10% of the total anthocyanin content only in 4 of 44 fruits listed in Table 4.3.1, in none of the 13 vegetables shown in Table 4.3.3, and in 2 grains and nuts presented in Table 4.3.4. Malvidin is widespread in all types of grapes being one of the major anthocyanidins found in grapes shown in Table 4.3.2. None of the foods listed in the tables presented malvidin as the sole aglycone. 

Berries, such as blueberries, bilberries, and black currants, are the main sources of cyanidin, delphinidin, malvidin, peonidin, and petunidin. Malvidin is the characteristic anthocyanidin of red grape and red wine. Plums, cherries, and red cabbage are rich in... 

In addition to the 18 anthocyanidins listed previously, Table 10.1 contains seven new desoxyanthocyanidins and a novel type of anthocyanidin called pyranoanthocyanidins. While 31 monomeric anthocyanidins have been properly identified, most of the anthocyanins are based on cyanidin (30%i), delphinidin (22%i), and pelargonidin (18%), respectively (Figure 10.2). Altogether 20%i of the anthocyanins are based on the three common anthocyanidins (peonidin, malvidin, and petunidin) that are methylated. Around 3, 3, and 2% of the anthocyanins or anthocyanidins are labeled as 3-desoxyanthocyanidins, rare methylated anthocyanidins, and 6-hydroxyanthocyanidins, respectively. 

FIGURE 10.2 The number of anthocyanins based on the various anthocyanidins. The upper dark part of each bar represents the anthocyanins reported later than 1992. Pg, pelargonidin Cy, cyanidin Pn, peonidin, Dp, delphinidin Pt, petunidin Mv, malvidin RMS, rare methylated structures 60H, 6-hydroxy- Des, desoxy- Pyr, pyrano- Sp, sphagnorubins. See Table 10.1 for structures. 

Each anthocyanidin is involved in a series of equilibria giving rise to different forms, which exhibit their own properties including color. One- and two-dimensional NMR have been used to characterize the various forms of malvidin 3,5-diglucoside present in aqueous solution in the pH range 0.3 to 4.5 and to determine their molar fractions as a function of pH. In addition to the flavylium cation, two hemiacetal forms and both the cis and trans forms of chalcone were firmly identified. In a reexamination, the intricate pH-dependent set of chemical reactions involving synthetic flavylium compounds (e.g., 4 -hydroxyflavylium) was confirmed to be basically identical to those of natural anthocyanins (e.g., malvidin 3,5-diglucoside) in... 

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). 

Anthocyanidins Pelargonidin Cyanidin Peonidin Delphinidin Petunidin Malvidin... 

The heterocycle of anthocyanidins is a pyrilium kation. Anthocyanidins are typically not found as free aglycones, with the excepton of the following widely distributed, colored compounds Pelargonidin (orange-red 1.45), cyanidin (red 1.46), peonidin (rose-red 1.47), delphinidin (blue-violet 1.48), petunidin (blue-purple 1.49), and malvidin (purple 1.50). A convenient mnemonic is PCP-DPM. The most common anthocyanidin is cyanidin. These compounds are present in the vacuoles of colored plant tissues such as leaves or flower petals. The color of the pigment depends on... 

There are about 17 anthocyanidins found in nature, but only 6 — cyanidin, delphinidin, petunidin, peonidin, pelargonidin, and malvidin—are ubiquitously distributed and of dietary importance. The variation of anthocyanins are due to (i) the number and position of hydroxyl and methoxy groups on the basic anthocyanidin skeleton (ii) the identity, number, and positions at which sugars are attached and (iii) the extent of sugar acylation and the identity of the... 

HPLC is the main separation technique for quantification of water-soluble, nonvolatile, thermally labile anthocyanins (Table 3.4). The columns most commonly used are reversed-phase C18. The pH of mobile phase is generally kept acidic with either formic, acetic, or trifluoroacetic acid. The order of elution follows the decreasing polarity of the anthocyanidins and is as follows delphinidin, cyanidin, petunidin, pelargonidin, peonidin, and malvidin. Disaccharide moieties in the C-3 position influence polarity less than the presence of the same two monosaccharides in C-3 and C-5 positions. Anthocyanins absorb visible light at 510-528 nm and UV light at 270-280 nm. DAD is the most common technique used for detection and quantification of anthocyanins, with the quantification occurring around the absorption... 

For the six common anthocyanidins delphinidin, cyanidin, petuni-din, pelargonidin, peonidin, and malvidin. 

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