Caffeic acid echinacea

Fig. 2.77 Compounds 246-249, caffeic-acid derivatives from Echinacea angustifolia. Compounds 250 and 251, sweet principals from Lippia dulcis...

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. 

Bauer R, Foster S. Analysis of alkamides and caffeic acid derivatives from Echinacea simulata and E. paradoxa roots. Planta Med 1991 57 447-449. 

The three most widely used species of Echinacea are Echinacea purpurea, E pallida, and E angustifolia. The chemical constituents include flavonoids, lipophilic constituents (eg, alkamides, polyacetylenes), water-soluble polysaccharides, and water-soluble caffeoyl conjugates (eg, echinacoside, chicoric acid, caffeic acid). Within any marketed echinacea formulation, the relative amounts of these components are dependent upon the species used, the method of manufacture, and the plant parts used. Epurpurea has been the most widely studied in clinical trials. Although the active constituents of echinacea are not completely known, chicoric acid from E purpurea and echinacoside from E pallida and E angustifolia, as well as alkamides and polysaccharides, are most often noted as having immune-modulating properties. Most commercial formulations, however, are not standardized for any particular constituent. 

FIG. 2 Major caffeic acid phenols (CAP) found in Echinacea. 

AVERAGE TOTAL CAFFEIC ACID PHENOL CONTENT (mg/g DRY ROOT) OF VARIOUS ECHINACEA SPECIES AND VARIETIES GROWN UNDER CULTIVATED AND WILD ENVIRONMENTS 1... 

Bergeron, C., Gafner, S., Batcha, L., and Angerhofer, C. 2002. Stabilization of caffeic acid derivatives in Echinacea purpurea L. glycerin extract. J. Agric. Food Chem. 50, 3967-3970. 

Kim, H., Durance, T., Seaman, C., and Kitts, D. 2000b. Retention of caffeic acid derivatives in dried Echinacea purpurea. J. Agric. Food Chem. 48, 4182-4186. 

Luo, X., Chen, B., Yao, S., and Zeng, J. 2003. Simultaneous analysis of caffeic acid derivatives and alkamides in roots and extracts of Echinacea purpurea by high performance liquid chromatography-photodiode array detection-electrospray mass spectrometry. J. Chromatogr. A 986, 73-81. 

Schieffer, G. 2000. Validated HPLC method for caffeic-acid derivatives and alkylamides of Echinacea solid-dosage forms using a single extraction procedure. J. Am. Nutraceutical Assoc. 3, 67-81. 

Echinacea is one of the best-selling herbal products in the United States (Brevoort, 1998) and is promoted as an immunostimulatory agent (Bauer, 1999a, 2000). The alkamides, caffeic acid derivatives (e.g., cichoric acid), glycoproteins, and polysaccharides are believed to be responsible for Echinacea s observed immunostimulatory activity. Bauer (1997) reported that the variation in alkamide concentrations of Echinacea products was due to a number of factors such as growing season, which part of the plant was utilized in the preparation of the commercial product,... 

Qualitative Evaluation of the Caffeic Acid Derivatives in Echinacea Species Using Micellar Electrokinetic Chromatography (Pietta et al., 1998)... 

In this chapter, we will discuss in brief about caffeic acid and compounds derived from it. Caffeic acid is regarded as the commonest of phenolic compounds distributed in plant flora, ft is produced by hydroxylation of cinnamic acid. Caffeic acid is distributed in Coffea arabica, Echinacea purpurea and Cichorium intybus. Qunic acid is the degradation product of caffeic acid. Chlorogenic acid is a dark coloured pigment and is most abundant phenolic compound in plants next to caffeic acid. It is known to cause allergic dermatitis among humans. 

Fig. 29A Methanolic extracts of the Echinaceae radix samples 1-3 and Partenium integrifolium (4) can be differentiated in UV-365 nm by their number, amount and R, range of blue fluorescent caffeic acid derivatives.

In a survey of 32 manufactured Echinacea products in the Australian marketplace, isobutylamides and cichoric acid (a caffeic acid derivative) were used as chemical markers to assess the quality and consistency of the products in the marketplace. The survey... 

Chlorogenic acid, caffeic acid, echinacoside, and cichoric acid were extracted from Echinacea roots and separated on a C g column (A = 300nm) using a 90/10 75/25 (at 30 min hold 5 min) water (0.1% H3P04)/acetonitriIe gradient... 

HPLC profiles of alcoholic extracts from Echinacea roots with caffeic acid derivatives. From [41... 

The roots of . purpurea do not contain echinacoside, but cichoric acid (2 ,3 -dicaffeoyl tartaric acid) and caftaric acid (monocaffeoyl tartaric acid) as shown in Figures 4 and 11. Cichoric acid was first found as a major constituent in the aerial parts of Echinacea species [82, 83]. Later it was found that it is abundant also in Echinacea purpurea roots and the content has been determined by HPLC to be 0.6-2.1% [84]. Schenk and Franke recently found 0.9% in cultivated material [15]. Cichoric acid undergoes rapid enzymatic degradation (see Echinacea purpurea aerial parts, section on caffeic acid derivatives and phenolic acids) [84]. Therefore, the quality of phytopreparations needs to be thoroughly checked. For analytical methods, see also Echinacea purpurea aerial parts. 

The main caffeic acid derivative in the aerial parts of Echinacea purpurea is cichor-ic acid (2R,3R-0-dicaffeoyl-tartaric acid). It was first isolated from the leaves of . purpurea by Becker and Hsieh [83]. Hsieh [106] reported no data on the optical activity of cichoric acid. The cichoric acid isolated later from . purpurea by Remiger [84] and by Soicke et al. [107] had an optical rotation [a] of ca. -370 . In contrast, the cichoric acid first isolated by Scarpati and Oriente [108] from Cichorium intybus displayed a rotation of +383.5 . Cichoric acid from lettuce Lac-tuca sativa) [109] and from endives (Cichorium endivia) [110] was also dextrorotatory. Synthetic studies by Scarpati and Oriente [108] showed that cichoric acid from Cichorium intybus contains a residue of (2S,3S)-(-)-tartaric acid. Conversely, that in... 

Three species of Echinacea are in medicinal use Echinacea ( .) purpurea E. angustifolia and . pallida. Depending on the species, the part of the plant (roots, herb) and the method of extraction (hydrophilic, lipophilic), the commercially available preparations of Echinacea contain varying concentrations of flavonoids, essential oils, polysaccharides, derivates of caffeic acid, polyacetylenes, alkylamides and alkaloids. Apart from a very few exceptions these preparations are not standardized in their content of any of these substances. The evidence available so far indicates that it is not a single component but the mixture of various groups of substances which is responsible for the observed immunomodulatory effects [5]. 

Reference substances with ascending hRf values lane 1 rutoside, camphorol 3-rhamnosido-glucoside, hyperoside, lane 2 chlorogenic acid, caffeic add, lane 3 the crude drug Echinaceae purpurea, lanes 4-7 various expressed juices of the same plant. 

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