Caffeic acid esters

Nakayama, T., Protective effects of caffeic acid esters against hydrogen peroxide-induced cell damage, Colloq. Sci. Int. Cafe, 16th(Vol.l), 372, 1995. (CA124 134741e)... 

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... 

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. 

One of the most important uses of many native aromatic plants in popular medicine is for digestive complaints [216]. Some studies suggest that EOs are responsible, at least in part, for the digestive activities of this group of plants, although it is also possible that other components (e.g. caffeic acid esters) also contribute to this activity [217, 218]. 

There are five deoxyanthocyanidins Apigeninidin (1.51), luteolinidin (1.52), 7-methoxyapigeninidin (1.53), 5-methoxy-luteolinidin (1.54), and the caffeic acid ester of arabinosyl 5-O-apigcninidin (1.55). 

The objective of this work was to study the demethylation of WEAX ester-linked ferulic acid in order to produce caffeic acid ester-linked onto WEAX, possibly oxidable into quinone and able to link an amino acid of a protein in a second step. To our knowledge, if free ferulic acid can be O-demethylated intact by some microorganisms,10 16 no microbial O-demethylation of linked methoxylated compounds has been reported in the literature. Three anaerobic bacteria (Acetobacterium woodi, Clostridium methoxybenzovorans and Eubac-terium callanderi) and one facultative aerobic bacterium (Enterobacter cloacae) have been chosen in different phylogenetic groups for their ability to O-demethylate free ferulic acid.10-13... 

Our investigations revealed the presence of calceolarioside B (23) in Fraxinus ornus leaves [28] and of six caffeic acid esters of PhGs in the polar part of the EtOH extract of the bark [29]. Five of them were identified as the known 2-(4-hydroxyphenyl)-ethyl-(6-0-caffeoyl)-p-D-glucopyranoside (22), calceolarioside B (23), verbascoside (24), isoacteoside (25) and lugrandoside (26). The occurrence of 22 and 26 in Oleaceae has not been reported so far. 

Rosmarinic acid (a-O-ca ffeoy i-3.4-di hydroxy phenyl act ic acid) (Figure 1) is an example of a caffeic acid ester occurring in plants. Rosmarinic acid is mainly found In species of the Boraginaceae and Lamiaceae families, but can also be detected in other families (i.e. Apiaceae), ferns and homworts (Table I) (3,d). This suggests that the ability to synthesize this cafTeoyl ester may actually be widespread as evidenced by rosmarinic acid accumulation in a range of species (Table I) (5). 

Rao, C.V., Desai, D., Simi, B., Kulkami, N., Amin, S., and Reddy, B.S. (1993) Inhibitory Effect of Caffeic Acid Esters on Azoxymethane-Induced Biocbemical Changes and Aberrant Crypt Foci Formation in Rat Colon, Cancer Res. 53, 4182-4188. 

Propolis contact allergy is not caused by one main allergen, but by several allergens varying in chemical composition the presence of these in propolis depends on the nature of the source plant and the place and time of collection by the bees [3]. Studies have shown that 1,1-dimethylallyl and 3-methyl-2-butenyl caffeic acid ester are the strongest sensitizers [3-6]. Propolis allergy today is seen mainly in individuals who use propolis as bio-cosmetics and in self treatment of various diseases [4]. 

Hausen BM, Wollenweber E, Senff H, et al. (1987) Propolis allergy (II). The sensitizing properties of 1,1-dimethylallyl caffeic acid ester. Contact Dermatitis 17 171-77... 

A resinous substance found in beehives (beeglue). Collected by bees from poplar buds. Contains fiavonoid aglycones and the main allergen is 1,1-dimethylallyl caffeic acid ester... 

Caffeate CoA ligase (D 22.2.1) p-Coumaric acid and caffeic acid esters of quinic acid I... 

Xing AT, Tian JM, Liu CM, Li HL, Zhang WD, Shan L (2010) Three new monoterpene alkaloids and a new caffeic acid ester from Incarvillea mairei var. multifoliolata. Helv Chim Acta 93 718-723... 

Hanefeld, M., and K. Herrmann Quantitative determination of caffeic acid esters and catechins by direct measurement on thin-layer chromatography. J. Chro-matogr. 123, 391—395 (1976). 

Caffeic acid ester distribution in higher plants. Z. Naturforsch. 21b, 604—605 (1966). 

Purpurein (107), isolated from the bark of Salix purpurea, was established as a diastereomer of grandidentatin by comparison of the de-/ -coumaroylated purpurein with grandidentin, a product of alkali hydrolysis of grandidentatin (92). The absolute stereochemistry of these two coumaroyl esters of l,2-c/5-hexane diol remains to be solved. Grandidentoside (108), another cyclohexane diol glucoside isolated from R grandidentata, was determined to be a caffeic acid ester of the similar glucoside (34). 

Yabuta G., Koizumi Y., Namiki K., Hida M., Namiki M. Structure of green pigment formed by the reaction of caffeic acid esters (or chloro-genic acid) with primary amino compounds. Bioscience, Biotechnology, and Biochemistry, 65 2121-2130 (2001). 

Hare, J.D., J.G. Millar R.F. Luck. 1993. A caffeic acid ester mediates host recognition by a parasitic wasp. Naturwissenschaften 80 92-94. 

Several caffeic acid esters of hydroxyacids (90,91,92,93) are known in ferns. Chicoric acid (90) is present in many ferns (54). o-Coumaric acid (70) and its P-D-glucoside, melilotoside (72) have been isolated together with coumarin (120) from Polystichum gemmiferum and Phy mat odes scolopendria (55). 

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