Chlorogenate hydrolase-catalyzed synthesis of hydroxycinnamic acid ester derivatives by transesterification, substitution of bromine, and condensation reactions

Abstract

A chlorogenate hydrolase (EC 3.1.1.42) synthesized 2-phenylethyl caffeate (2-CAPE) from 5-chlorogenic acid (5-CQA) and 2-phenylethyl alcohol (2-PA) (by transesterification), from 5-CQA and 2-phenylethyl bromide (2-PBr) (by substitution of bromine), and from caffeic acid (CA) and 2-PA or 2-PBr (by condensation) as well as hydrolysis of 5-CQA. Some reaction conditions including pH, temperature, substrate and solvent concentrates, and reaction time were optimized for the production of 2-CAPE. A maximal molar yield of 50% was achieved by transesterification, 4.7% by substitution of bromine, and 13% by condensation. Among the parameters studied for optimization, the pH of the buffer solution and concentration of 2-PA or 2-PBr affected the production of 2-CAPE. The optimum pH for the hydrolysis reaction was within the neutral range (pH 6.5), whereas the residual three reactions were only catalyzed within the acidic range (pH 3.0-4.0). The optimum concentrations of 2-PA and 2-PBr for three reactions were 5-70 vol% and no 2-CAPE was produced in the 2-PA or 2-PBr solutions containing powdered enzyme. The enzyme may bind to the caffeoyl moiety of 5-CQA or CA to form an enzyme-substrate complex. It then catalyzes four different reactions corresponding to the reaction conditions.

Enzymatic synthesis of caffeic acid phenethyl ester analogues in ionic liquid

“…Using the procedure, we synthesized CAPE analogues, namely, 48.8 mM 2-cyclohexylethyl caffeate, 46.9 mM 3-cyclohexylpropyl caffeate, 49.4 mM 4-phenylbutyl caffeate, and 42.0 mM 5-phenylpentyl caffeate with conversion yields of 97.6%, 93.8%, 96.7%, and 84.0%, respectively. In terms of the conversion yield, this procedure is superior to the previous procedure affording CAPE with the maximum conversion yield of 50% (Kishimoto et al, 2005a). CAPE was obtained by transesterification catalyzed by Novozyme 435 using isooctane as the solvent with the conversion yield of 91.65% (Chen et al, 2010).…”

Role of hydroxycinnamates in coffee melanoidin formation

“…The chlorogenate hydrolase (EC 3.1.1.42) from Aspergillus japonicus has a higher specificity for chlorogenic acid but also has hydrolase Phytochem Rev (2010) 9:171-185 179 activity for caffeoyl tartaric acid, coumaroyl tartaric acid, and for the ethyl and benzyl esters of cinnamic acid. However, it does not act on ethyl esters of crotonic (2-E-butenoic) and acrylic (propenoic) acids neither on esters of hydroxybenzoic acids (Okamura and Watanabe 1982;Kishimoto et al 2005). To perform the hydrolysis, the enzyme needs an intact cinnamoyl structure.…”

Biotransformation of Underutilized Natural Resource to Valuable Compounds in Ionic Liquid: Enzymatic Synthesis of Caffeic Acid Phenethyl Ester Analogues from Immature Coffee Beans

“…The conversion yields are shown in Table 3. In terms of the conversion yield, this procedure using Novozyme 435 is superior to the previously reported procedure affording CAPE with the maximum conversion yield of 50% (Kishimoto et al, 2005a). CAPE was obtained by transesterification catalyzed by Novozyme 435 using isooctane as the solvent with the conversion yield of 91.65% (Chen et al, 2010).…”

“…The net conversion yield of 3-cyclohexylpropyl caffeate toward 5-caffeoylquinic acid was 85.3%. In the synthesis of CAPE analogues, the conversion yield of 3-cyclohexylpropyl caffeate toward 5-caffeoylquinic acid (85.3%) was superior to that of CAPE toward 5-caffeoylquinic acid (50%) (Kishimoto et al, 2005a). CAPE analogues were obtained by single transesterification systems catalyzed by Novozyme 435 using [bmim][NTf 2 ] or isooctane as the solvent with conversion yields of 93.8% and 91.65%, respectively (Chen et al, 2010;Kurata et al, 2010).…”

“…Immature green coffee beans are not marketed as coffee because contamination of these beans negatively affects the flavor. However, they contain appreciable amounts of various caffeoylquinic acids, for example, 4.8-5.8 g of 5-caffeoylquinic acid/100 g of immature green coffee beans (Kishimoto et al, 2005a). These immature beans are notable among unused agricultural resources, and we are therefore currently investigating the enzymatic conversion of their caffeoylquinic acids to valuable products.…”