Gallic acid derivatives

We also need to point out the often improper use of proanthocyanidin nomenclature. In Ref. 104, both vitisinol (125) and amurensisin (126) were classified as procyanidins per definition they do not belong to this class of compounds (Figure 11.11). Vitisinol (125) is rather a member of the nonproanthocyanidin class with flavan or flavan-3-ol constituent units (see Section 11.3.3), while amurensisin (126) is simply a gallic acid derivative of epicatechin (see Section 11.3.1.2). 

Epilobium parviflorum Schreb. Flavonoids, sitosterol, gallic acid derivatives.147 Antiphlogistic. 

Glycosides, particularly of phenolic compounds, are widely distributed in plant tissues (2,10). Glycosides of anthocyanidins, flavones, flavanols, flavanones, flavanonols, stilbenes and saponins, gallic acid derivatives, and condensed tannins are all common. 

Further analysis of the UV spectrum revealed that this compound is a gallic acid derivative. A search of the Dictionary of Natural Products for molecular ion and plant genus name leads to the identification of a known compound - Pterocaryanin B. The compounds with poly-hydroxyl groups in their structures are very well known as tyrosinase inhibitors and are responsible for the inhibition of melanin synthesis. Therefore, no further isolation was necessary. 

Scheme 27. Lead(IV)-mediated oxidative dimerization of gallic acid derivatives.

Scheme 28. Lead(IV)-mediated oxidation (Wessely reaction) of a simple gallic acid derivative without biaryl formation.

Figure 2.67 Synthesis of liquid-crystalline analogues of the manganese cluster Mnl2 , [Mni20i2(0Ac)i6(H20)4], and structure of the gallic acid derivatives HLS HL and HL ...

One of the most effective and widespread antioxidants are the tocoph-erols (vitamin E), polyphenol (catechol, Gallic acid derivatives), flavo-noids (routine, quercetin), ascorbic acid. The most perspective objects of the antioxidants are the plant facilities. 

Haslam E (1989) Gallic acid derivatives and hydrolyzable tannins. In Rowe JW (ed) Natural products of woody plants chemicals extraneous to the lignocellulosic cell wall, vol 1. Springer, Berlin... 

Haslam, E. (1989). Gallic acid derivatives and hydrolyzable tannins. In Natural Products of Woody Plants Chemicals Extraneous to the Lignocellulosic Cell Wall, Vol. 1 (ed. J.W. Rowe), pp. 399-438. Springer-Verlag, Berlin. 

Gallic Acid Derivatives and Hydrolyzable Table 7.2.4. Polygalloyl esters based upon )ff-penta-0-galloyl-D-glucose (15) ... 

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