Polyphenol, interactions with membranes

The localization of the polyphenolic compounds inside liposomes depends on their lipophilic character. Some of these molecules are located in the hydrophobic bilayer of the liposomal membrane and are associated with the apolar moieties of phospholipids through hydrophobic interactions more hydrophilic polyphenols associate with the polar heads of phospholipids through hydrogen bondings. 

Overall, these studies substantiate the notion that polyphenols, in a structure-dependent way, are capable of interacting with membranes and lipoproteins and, at this location, may attain a local concentration high enough to act as antioxidants via regeneration of a-TOH. 

Table VI shows the rejection measured for total N2, polyphenols and sugars with DDS 800 and PA 300 membranes. Sugar rejections increased from about 20% with DDS 800 to 100% with PA 300. Table VII shows the rejections of various cations using the PA 300 membrane. The rejection for the majority of cations is higher than 97%. Only Cu" " and Zn" " permeate easily through the membrane. The rejections for these two cations is essentially zero. The reason is attributed to a high specific interaction of Cu and Zn with the polymeric materials forming the membranes and to Donnan equilibrium.

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