Hydroxycinnamic Acid Esters

Okamura, S. and Watanabe, M., Purification and properties of hydroxycinnamic acid ester hydrolase from Aspergillus japonicus. Agric. Biol. Chem. 46, 1839, 1982. 

Price, K.R., Causcelli, F., Colquhoun, I.J., and Rhodes, M.J.C., Hydroxycinnamic acid esters from broccoli florets. Phytochemistry, 45, 1683, 1997. 

For hydroxycinnamic acid derivatives in citrus products, an HPLC method was also applied to determine the hydroxycinnamic acid esters with glucose or aldaric acids in the peel and pulp... 

Hydroxycinnamic Acid Esters During Fermentation and Aging of Merlot and Cabernet Sauvignon, Am.J. Enol. Vitic. 1979, 30, 111-116. 

Nagel, C. W., Wulf, L. W. (1979). Changes in the anthocyanins, flavonoids and hydroxycinnamic acid esters during fermentation and aging of merlot and cabernet sauvignon. Am. J. Enol. Vitic., 30, 111-116. 

Hydroxycinnamic acid esters, e.g. chlorogenic acid, can act as activated hydroxycinnamoyl donors as well, and thus represent an activated form of a hydroxycinnamic acid. This will be exemplified in more defail in Sections 4.2.1.4 and 4.2.2. 

Strack, D., Gross, W., Heilemann, J., Keller, H. and Ohm, S. (1988) Enzymic synthesis of hydroxycinnamic acid esters of glucaric acid and hydroaromatic acids from the respective 1-O-hydroxycinnamoylglucoside and hydroxycinnamoyl-coenzyme-A thioester as acyldonors with a protein preparation from Cestrum elegans leaves. Z. Naturforsch., 43c, 32-6. 

Strack, D., Keller, H., Weissenbock, G. (1987a) Enzymatic synthesis of hydroxycinnamic acid esters of sugar acids and hydroaromatic acids by protein preparations from rye (Secale cereale) primary leaves. /. Plant Physiol, 131, 61-73. 

Benzoic esters and acids -COOR and -COOH /7-hydroxycinnamic acids (ester and/or ether-Unked)... 

Biomimetic syntheses involving oxidative coupling are a source of constant fascination although they are rarely of synthetic use (cf. section 4.1). Two recent examples are shown in scheme 3. Oxidative coupling of the 4-hydroxycinnamic acid esters (19a) and (19b) affords the dihydronaphthalenes (20a) and (20b) respectively as the major products [40]. 

The role of CYP98A3 in phenylpropanoid biosynthesis was validated by the analysis of the refS mutant. As a result of the lack of C3 H activity, and as would be expected based upon its re.f phenotype, the refS mutant lacks sinapoylmalate. Further, saponification of leaf extracts yielded high levels of p-coumaric acid, indicating that refS accumulates />-coumaric acid esters that are not normally found in wild-type plants. The presence of these novel compounds demonstrates a degree of plasticity in hydroxycinnamic acid ester synthesis in... 

Strack D, Becher A, Brail S, Witte L (1991) Quinolizidine alkaloids and the enzymatic syntheses of their cinnamic and hydroxycinnamic acid ester in Lupinus angustifolius and L. luteus. Phytochemistry 30 1493-1498... 

Two mechanisms can be envisioned for the Pechmann condensation (1) acid-catalyzed transesterification of the P-keto ester followed by acid-catalyzed cyclodehydration of the resulting aryl acetoacetate (4), or (2) acid-catalyzed Friedel-Crafts-like phenol alkylation ortho to the phenolic hydroxyl group) followed by intramolecular transesterification/cyclization of the resulting o-hydroxycinnamic acid ester (5). 

The intermediacy of o-hydroxycinnamic acid esters (5) in the Pechmann condensation was first proposed by Pechmann in 1884. In 1932, Robertson and co-workers provided support for this proposal through their examination of the reactions of w-methylanisole and dimethylresorcinol with ethyl acetoacetate under the conditions of the Pechmann condensation. Allowing these anisoles to stand with ethyl acetoacetate in sulfuric acid resulted in the formation of 4,7-dimethylcoumarin and 7-methoxy-4-methylcoumarin, respectively. 3 -(2-Methoxy-4-methylphenyl)-2-butenoic acid could likewise be converted to 4,7-dimethylcoumarin under similar conditions. These observations revealed cinnamate intermediates such as 5 to be viable intermediates in the Pechmann condensation and demonstrated that the formation of aryl acetoacetate intermediates such as 4 is not required for coumarin formation. 

Takahama, U. Oniki, T. (1998). 3,4-Dihydroxy-phenylalanine is oxidized by phenoxyl radicals of hydroxycinnamic acid esters in leaves of Vida faba L. Journal of Plant Research, 3, 487-494. 

Kadota, S. Tezuka, Y. (2004). Study on antimetastatic activity of a propolis constituent, cape, and its analogues. Honeybee. Set, 25, 3,107-112 Kishimoto, N. Kakino, Y. Iwai, K. Fujita, T. (2005a). Chlorogenate hydrolase-catalyzed synthesis of hydroxycinnamic acid ester derivatives by transesterification, substitution of bromine, and condensation reactions. AppZ, Microbiol Biotechnol, 68, 2,198-202... 

Hydroxycinnamic Acid Esters.- Enzymes catalysing the esterification of quinic acid with p-coumaroyl CoA and caffeoyl... 

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