Malvidin antioxidant activity

The red wines have an abundance of anthocyanins such as delphini-din 3-0-/i-L)-glucosidc, petunidin 3-0-/ -D-glucoside, malvidin 3-0-/3-D-glucoside, and cyanidin 3-0-/J-o-glucosidc from grape skins [33,34], These anthocyanins also might have antioxidant activity against the oxidation of LDL [11]. 

In products with complex combinations of various types of flavonoids and other phenolic compounds, effort has been made to ascribe the antioxidant activity of the product to different classes of polyphenols. Frankel et al. (1995) studied 20 selected California wines and related the antioxidant activity to the polyphenolic components of the wines, rather than to resveratrol. Antioxidant activity was measured by the ability of the wines to inhibit copper-catalyzed oxidation of human LDL. The correlation coefficient between antioxidant activity and total phenolic components of the wines was r = 0.94. Individual phenolic compounds (gallic acid, catechin, myricetin, quercetin, caffeic acid, rutin, epicatechin, cyanidin, malvidin-3-glucoside) contributed to the antioxidant activity. The correlation coefficient for the compounds ranged from r = 0.92 to r = 0.38 in descending order. 

Grapes, wine and other berry products are acidic, and the anthocyanins are in the flavylium form. A hypothesis that the anthocyanins may be pH-transformed into their carbinol pseudo-base and quinoidal base, or the chalcone, in the intestine and blood system during digestion has been proposed by Lapidot et al. (1999). These compounds have been shown to have antioxidant activity and are also most likely absorbed from the gut into the blood system. The pseudo-base and the quinoidal base of malvidin and malvidin-3-glucoside remained as very effective antioxidants, both when tested by a linoleate-oxidizing assay and by a microsomal lipid peroxidation assay. 

Proteins have strong binding properties with flavonoid antioxidants in foods and biological systems, and generally increase the oxidative stability of liposomes. The addition of bovine serum albumin (BSA) increased the oxidative stability of a lecithin-liposome and changed the relative antioxidant activity of various pairs of flavonoids and phenolic acids (Table 10.13). In the absence of BSA, the activity of phenolic antioxidants decreased in the order ferulic acid > epicatechin > catechin > malvidin > caffeic acid quercetin > propyl gallate. In the presence of BSA, the activity of malvidin increased, followed by rutin and ferulic acid, but the activity of epicatechin and catechin decreased. 

Cyanidin, delphinidin, petunidin, peonidin, pelargonidin, and malvidin are the most common anthocyanins in nature [125]. Their antioxidant, antiinflammatory, and detoxification activities justify their preventive roles against cancer and cardiovascular diseases. 

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