Flavonoid with macromolecules

Tannins are considered polyphenols due to the large number of phenolic rings in their structures (Mosiewicki et al., 2007 Moubarik et al., 2009). These natural products can be found in certain plant tissues, such as bark, fruit and wood, and can be removed from these sourees by extraction with water. Tannins are classified in two groups hydrolyzable tannins and condensed tannins (Mueller-Harvey, 2001). The condensed tannins are flavonoids with complex structures (Fig. 2.5). The phenolic groups present in tannin enable this macromolecule to participate in the same reactions as phenol (Tondi and Pizzi, 2009). Condensed tannins are more suitable than the hydrolyzable type for use in the manufacture of a phenolic-type polymeric matrix due to the presence of phenolic rings with a greater number of free positions where the electrophilic attack can occur (Barbosa et al., 2010). The high reactivity of... 

Alterations in the capillary filtration of macromolecules are well documented in diabetic patients and experimental diabetes. Various flavonoids, including anthocyanins and ginkgo biloba extracts, have been shown to be effective against experimentally induced capillary hyperfiltration. Cohen-Boulakia et al." demonstrated that anthocyanins were effective in preventing the increase in capillary filtration of albumin and the failure of lymphatic uptake of interstitial albumin in male rats with streptozotocin-induced diabetes. In an earlier study, Valensi and coworkers demonstrated in a placebo-controlled trial that a purified micronized flavonoid fraction (Daflon 500 mg) can improve and even normalize capillary filtration of albumin in diabetic patients. 

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