Caftaric acids

In addition to chemotype patterning revealed by statistical analysis of the data, latitudinal relationships emerged as well. Concentrations of cichoric acid and echinacoside and one of the amides, undeca-2Z,4Z-diene-8,10-diynoic acid 2-methylbutyl amide [246], with a larger amine-bearing group increased with latitude. The inverse relationship was observed for caftaric acid and hexadeca-2 , 9Z-diene-12,14-diynoic acid isobutylamide. The latitudinal differences may be of importance in helping to identify populations for selection of seed for propagation. 

Gonthier MP, Remesy C, Scalbert A, Cheynier V, Souquet JM, Poutanen K and Aura AM. 2006. Microbial metabolism of caffeic acid and its sters chlorogenic and caftaric acid by human faecal microbiota in vitro. Biomed Pharmacother 60 536-540. 

Fig. 2.79. Chromatograms of a white (I) and red wine sample (II). (LC-DAD signals at three different wavelenghts 256, 324, 365 nm). Peak identification 1 = gallic acid 2 = protocatechuic acid 3 = p-hydroxybenzoic acid 4 = vanillic acid 5 = caffeic acid 6 = (+)-catechin 7 = syringic acid 8 = p-coumaric acid 9 = ( — )-epicatechin 10 = ferulic acid 11 = fraras-resveratrol 12 = rutin 13 = myricetin 14 = cw-resveratrol 15 = quercetin A = caftaric acid B = coutaric acid. Reprinted with permission from M. Castellari et al. [196],...

The purple coneflower Echinacea purpura, and its close relatives, E. angustifolia and E. pallida, are the source of the herb Echinacea, which is widely popular as a nonspecific immune stimulant. These perennials are native to the prairies of North America and are now widely grown garden ornamentals. The root and aerial parts of the plant are the portions used, and the preparation s potency can be verified by the transient tingling sensation produced when it is tasted. Echinacea contains alkamides, caffeic acid esters (echinacoside, cichoric acid, caftaric acid), polysaccharides (heteroxylan), and an essential oil. Some echinacea products are standardized for their echinacoside content. In the past, adulteration with American feverfew (Parthenium integri-folium) was common. Echinacea is now sold either by itself or in combination with golden seal or zinc for the treatment of colds and influenza. 

Further effects on the polyphenol content of the wines were seen in this trial (Tao et al., 2007), including greater losses of catechin and mal-vidin-3-glucoside imder low SO2 conditions by contrast, more quercetin was lost in the MOX wines under a higher SO2 content, which can be potentially related to the limited ability of SO2 to reduce quercetin qui-nones (Makhotkina and Kilmartin, 2009), along with further reaction products arising from the interaction of quercetin with SO2. By contrast, hydroxycinnamic acids such as caftaric acid and caffeic acid were largely unaffected by MOX while adequate concentrations of free SO2 were maintained in the wines. 

Singleton, V. L., Salgues, M., Zaya, J., and Trousdale, E. (1985). Caftaric acid disappearance and conversion to products of enzymic oxidation in grape must and wine. Am.. Enol. Vitic. 36, 50-56. 

However, in view of quantities consumed by other populations, wines could make a significant contribution for tartaric acid conjugates and grapes and grape juice for caftaric acid, respectively. Lettuce is the major source of chicoric (dicaffeoyltartaric) and caffeoylmalic acid (up to 3 mg/100 g), but endive may have twice the concentration. Spinach is almost certainly the richest source of conjugated p-coumaric acid at some 30-35 mg/100 g [18]. 

Figure 11.3.1 HPLC chromatogram of acidic polyphenolics isolated from Niagara grapes and detected at 320 nm. Retention time 8.647 min, frans-caftaric acid 13.789 min, c/s-coutaric acid 14.944, frans-coutaric acid. Reproduced from Lee and Jaworski (1987) with permission from the American Society for Enology and Viticulture.

Retention times of the peaks are subject to the particular type of column. The acidic fraction from solid-phase extraction consists of phenolic acids such as cis-coutaric, trans-coutaric, and trans-caftaric acids. Isocratic elution is suitable because of the limited number of compounds found in the acidic fraction. Analysis of the acidic fraction is completed within 30 min. See Figure 11.3.1 for an HPLC chromatogram of the acidic polyphenolics isolated from Niagara grapes. 

Tartaric acid Feruloyl (i.e., ferulic acid) 2,3-O-dicaffeoyltartaric acid (Cichoric Acid) R1, R2 = X 2-0-caffeoyl-3-0-feruloyltartaric acid R1 = X, R2 = Y 2-O-caffeoyltartaric acid (Caftaric acid) R1 = X, R2= H... 

Precursors. Precursors for this reaction are anthocyanins and t -quinones of caf-feoyltartaric (caftaric acid) and p-coumaroyltartaric (cutaric acid) acids generated by enzymatic oxidation by grape polyphenoloxidase (PPO) (Singleton et al. 1985). PPO first adds an OH group to monophenols and then oxidizes the resulting o-diphenol to o-quinone. 

Mechanism of reaction. Under oxidative conditions and for grapes containing high levels of hydroxycinnamic acids and low of levels of glutathione (a compound that easily reacts with o-quinones, preventing oxidation of phenolic compounds in wines) (Sarni-Manchado et al. 1995), some phenolics are able to react with the o-quinones of caftaric acid (Cheynier et al. 1986) (see also Chapter 9B). 

Cheynier, V., Van Hulst, M. W. (1988). Oxidation of trans-caftaric acid and 2-S-glutathionyl caftaric acid in model solutions. J. Agric. Food Chem., 36, 10-15. 

Among the hydroxycinnamic acids, caftaric acid predominates (up to 50% of total hydroxycinnamic acids). Other important substances are the tartaric esters of p-coumaric acid and ferulic acid, and the franx-p-coumaric glucoside (Somers et al. 1987). The concentration levels of hydroxycinnamic acid derivatives in wine depend on many factors like grape variety, growing conditions, climate, etc. It is... 

Other pigment families have been shown to occur in red wine, like anthocyanin oligomers (Salas et al. 2005 Vidal et al. 2004a), caftaric acid-anthocyanin adducts (Sarni-Manchado et al. 1997) or catechin-pyrylium derived pigments (i.e., oaklins) resulting from the reaction between catechin and wood aldehydes, like coniferalde-hyde or sinapaldehyde (de Ereitas et al. 2004 Sousa et al. 2005). These... 

All HPLC injections were performed in duplicate. (+)- Catechin and (-)-epicatechin, 280 nm, and quercetin, 365 nm (Aldrich, Milwaukee, WI), caffeic acid, 316 nm(Sigma, St. Louis, MO), gallic acid (MCB Manufacturing Chemists, Cincinnati, OH) and malvidin-3-glucoside, 520 nm (Pfaltz Bauer, Waterbury,CT) were used as external standards at the indicated wavelengths. Caftaric acid was purified in our laboratory by a previously described method (31). The quercetin glycoside is expressed in quercetin equivalents, and all anthocyanins in malvidin-3-glucoside equivalents. 

Specific Phenolic Compounds. The concentrations of caffeic and caftaric acids (hydroxycinnamates), and gallic acid (a benzoic acid) did not significantly differ from the control wine by the use of any of the fining agents at any of the levels tested. 

Fining Agent Used Fining Agent Level (mg/L) Folin-Ciocalteau mgA. GAE) Gallic Acid Catechin Epicatechin t-Caftaric Acid CaffeicAcid Malvidin-3- Glucoside A... 

FIGURE 3.4 Structures of (a) chlorogenic acid, (b) caftaric acid, (c) ellagic acid and (d) resveratrol. [Source Adapted from Spanos and Wrolstad (1992) and Macheix and Fleuriet (1998).]... 

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