Gallic esters

When the lateral substituents were changed from ether to gallic ester groups, a columnar hexagonal phase was observed for 112, while complexation with KI destroyed the mesomorphic behavior [121] (Scheme 58). The presence of ion pairs in the complex presumably leads to unfavorable interactions between neighboring molecules leading to non-mesogenity. 

C. Dufour, E. Da Silva, P. Potier, Y. Queneau, and O. Dangles, Gallic esters of sucrose as efficient radical scavengers in lipid peroxidation, J. Agric. Food Chem., 50 (2002) 3425-3430. 

Some experiments have demonstrated that tannic acid, also called simply tannin , a natural mixture of gallic esters of glucose classically obtained from Rhus species (Anacardiaceae), interferes with cellular activation of PKC. It inhibited, for example, the phosphorylation catalysed... 

In the rosary pea Abrus precatorius L. Trigollenine as well as its gallic acid ester Precatorine (209) is found (71P195) (Scheme 69). 1-Carboxymethyl-nicotinic acid (210) was isolated as a colorless solid from the marine sponge Anthosigmella cf. raromicrosclera as a cysteine protease inhibitor (98JNP671). This compound was first synthesized in 1991. The sodium... 

Gallic acid propyl ester N-propyl gallate propyl 3,4,5-trihydroxy-benzoate... 

Flavanols/Procyanidins Catechin, epicatechin, and their gallic acid esters Apples, grapes, plums, pears, mangoes, okra, peaches, Swiss chard, berry fruits and vegetables in general,... 

There is the often-overlooked group of polyphenols containing the derivatives of hydro-xycinnamic and hydroxybenzoic acids such as caffeic, chlorogenic, and gallic acids (Figure 29.8), which occur in food and exhibit certain antioxidant activity. For example, some caffeic acid esters isolated from propolis from honeybee hives showed antiinflammatory... 

Building blocks Gallic acid, galloyl ester, ester-linked with glucose Flavanoid units (Procyanidins), catechin... 

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