Abstract Caffeic acid phenethyl ester (CAPE) is a main ingredient of propolis。 It has the antioxidant, anti-inflammatory, and anti-tumor activity。 Because of the low yield and various by-products after extracting and chemical synthesizing methods, enzymatic synthesizing CAPE has become the research hotspot。 In this paper, enzymatic synthesis process of CAPE with multiphase was conducted, and strengthened the technological process by microreactor, and preliminarily discussed the antibacterial activity of CAPE。
HPLC analysis methods of CAPE and caffeic acid ester extract were established, and the substrate MC was prepared。 CAPE was synthesized by multiphase enzymatic pathways with the substrates of MC and phenyl ethanol。 CAPE yield was obtained of 89。3 % with the conditions of Ionic liquid [Bmim][Tf2N], complexing agent reaction as multiphase reaction medium, catalyst of Novozym 435, 75 oC of reaction temperature, 1:20 of substrate molar ratio, 60 h of reaction time。
HPLC analysis method was used to detect the components of propolis, including MC, EC, AC, PC, BC and CAPE。 CAPE yield was obtained of 74。2 % with conditions of MC as the substrate, 1:15 of the substrate ratio, 48 h of reaction time under the condition of the same reaction medium and catalyst。
CAPE was synthesized by multiphase enzymatic pathways in microreactor with the substrates of MC and benzyl alcohol, and the factors of flow rate and temperature were studied。 CAPE yield was obtained of 67。9 % in 2。5 h with the conditions of 3 g/L substrate concentration, 1:15 molar ratio of coffee acid methyl ester and benzene ethanol, 65 oC of reaction temperature, 2 μL/min of flow rate。 Compared with the common reactor, the reaction time is reduced to 1/24。
The antibacterial effect of CAPE on Ralstonia solanacearum was studied。 The inhibitory effect of CAPE on the growth of Ralstonia solanacearum was proved by inhibition zone。 The highest inhibition rate was obtained of 64。3 % by culturing 24 h when the concentration of CAPE was 2。0 g/L。 When CAPE concentration was set as 1 g/L, the inhibition rate was obtained the maximum of 67。3 % by culturing 48 h。