Phenolic ellagic acid

A number of plant natural products have been isolated that inhibit an aspartic protease secreted by Candida albicans [35, 36], the most potent of which (IC50 values 8-14 pM) are the phenolics ellagic acid [35] and mattucinol-7-0-[4",6"-0-(5)-hexahydroxydiphenoyl]-P-glucopyranoside [35] and the triterpene betulinic acid [36] (Table 1). A macromolecule from Anchusa is a potent inhibitor of pepsin (K 20 nM) [37] (Table 1). 

ANCos B DE, GONZALES E M and CANO M p (2000) Ellagic acid, vitamin C, and total phenolic contents and radical scavenging capacity affected by freezing and frozen storage in raspberry fruit , J Agric Food Chem, 48 (10) 4565-70. 

Some phenolic acids such as ellagic acid can be used as floral markers of heather honey (Cherchi et al., 1994 Ferreres et al., 1996a,b), and the hydroxyciimamates (caffeic, p-coumaric, and ferulic acids) as floral markers of chestnut honey (Cherchi et al., 1994). Pinocembrin, pinobanksin, and chrysin are the characteristic flavonoids of propolis, and these flavo-noid compounds have been found in most European honey samples (Tomas-Barberan et al., 2001). However, for lavender and acacia honeys, no specific phenolic compoimds could be used as suitable floral markers (Tomas-Barberan et al., 2001). Other potential phytochemical markers like abscisic acid may become floral markers in heather honey (Cherchi et al., 1994). Abscisic acid was also detected in rapeseed, lime, and acacia honey samples (Tomas-Barberan et al., 2001). Snow and Manley-Harris (2004) studied antimicrobial activity of phenolics. 

Phenolic (benzoic) acids Ellagic acid Strawberries Muscadine grapes... 

The differences between castoreum from different species and sources still need to be investigated. As suggested by Tang et al [69] it is quite likely that these differences could be diet related because the phenols are most likely derived from the diet of these animals. Indeed, already in 1949 Lederer [73] recognized this possibility and pointed out that 2, 3"-dihydroxydibenz-2-pyrone and 4,4 -dihydroxydiphenic acid dilactone 12 (Fig. 3) are closely related to ellagic acid, which is abundant in the bark of trees. A comprehensive chemical analysis of the polyphenols present in the preferred diet of the beavers and a comparison of these compounds with the phenols present in castoreum from animals fed exclusively on this diet could shed some light on this unresolved problem. 

In the adsorption of some metal ion by tannin adsorbents [16], tannins are widely distributed in nature and have multiple adjacent phenolic hydroxyl groups and exhibit specific chelation ability toward metal ions [17]. According to the chemical stractures of tannins, they can usually be classified into hydrolyzable tannins, condensed tannins and complex tannins. Hydrolyzed tannins yield galhc acid or ellagic acid when hydrolyzed by acid, base or some enzymes [18]. Turkish sumac tannin (hydrolyzable tannin) is illustrated in Fig. 28.1 whose basic stracture is of flavan-3-ols. 

N.A. Lycopus virginicus L. Phenolic acids, caffeic derivatives, chlorogenic derivatives, ellagic acids." Treat overactive thyroid gland, an astringent to reduce the production of mucus. 

Hydrolyzable Tannins. The hydrolyzable tannins are composed of one glucosidic molecule to which are bonded different phenolic moieties the most important of these are gallic acid (15) and the lactone of its dimer, ellagic acid (16). These are not the natural tannins of grapes, but they are the principal commercial tannins (tannic acid) authorized by legislation to be added to wines. The oak tannins also belong to this family and may be added to wines stored in wooden casks. The presence of ellagic acid in wine, reported in the literature, needs to be confirmed. 

Esters (RCOOR) are formed by reaction of a carboxylic acid with the hydroxyl group of an alcohol. The hydroxyl group of phenolic compounds can participate in ester formation. Esters of two phenols are not particularly common in nature. The most familiar is the diester of gallic acid (2.22), which is ellagic acid (2.23), along with other gallotannin compounds. 

This procedure is based on the formation of the electophile NO+, which can react with an ellagic acid residue (4.2) at two sites, either via a substitution reaction which results in 4.3, or an addition reaction that results in the nitrosyl dienone 4.4. These compounds can decay to form the quinine oxime 4.5, which under alkaline conditions forms the red product 4.6. When related compounds, such as gallic acid, phloroglucinol, hydroxycinnamic acids, and phenol are subjected to this assay, a yellow-brown product is formed, which does not interfere with the spectrophotometric detection of ellagic acid. 

Tannins Gallic acid 45 is a phenolic compound found mainly in grape seeds and stems, but also it can be leached from oak barrels, occurring generally in amounts of 10-100mg/L. Two molecules of gallic acid in a head-to-tail fashion are the dilactone ellagic acid 46 ... 

Ellagic acid (= Benzoaric acid Lagistase) (phenolic acid lactone) Widespread, ellagitannin product Psidium guajava (Myrtaceae), Fragaria spp. (Rosaceae) ACE (34% inhibition at 300 pM) [76]... 

Fig. 5-8. Examples of phenolic extractives and related constituents. 1, Gallic acid 2, ellagic acid 3, chrysin 4, taxifolin 5, catechin 6, genistein 7, plicatic acid 8, pinoresinol 9, conidendrin 10, pinosylvin 11, /3-thujaplicin.

Ellagic acid (= Benzoaric acid Lagistase) (phenolic acid lactone)... 

Ellagic acid (phenol) Widespread Euphorbia pekinensis CHS II (at 100) (CA)... 

Ellagic acid derivatives, variously acetylated alkylated] (phenolic lactone) Semi-synthetic derivatives of Ellagic acid AR (rat lens) (0.1 to > 10)... 

Priyadarsini Kl, Khopde SM, Kumar SS, Mohan H. (2002) Free radical studies of ellagic acid, a natural phenolic zntioTddznt. JA r Food Chem 50 2200-2206. 

Lyophilized hairy roots, cultured in hormone-free B5 liquid medium for 4 weeks, were extracted as above and subjected to the combination of column chromatographies using Sephadex LH-20 and MCI-gel CHP-20P to afford six phenolics, 1, 2,8, 12, 13 and ellagic acid (16) (Fig. 4). These phenolics obtained from the hairy roots were also isolated from the leaves of the intact plant of G. thunbergii. 

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