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Updated: Nov 16, 2025

Author Spotlight: Eco-Friendly Extraction of Bioactive Compounds Using Polyol-Based Microwave-Assisted Techniques
Published on: August 23, 2024
Chemoenzymatic semisynthesis of caffeic acid β-phenethyl ester, an antioxidative component in propolis, from raw
Riichi Hashimoto1, Hiyori Iai2, Rie Fujita1
1Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, Shibakoen, Minato-ku, Tokyo, Japan.
Abstract:
Caffeic acid β-phenethyl ester (CAPE), an antioxidative bioactive catechol isolated from propolis, was semisynthesized from chlorogenic acid and related compounds in an extract of raw (unroasted) Robusta coffee (Coffea canephora) beans in 5 steps and a total yield of 31%. Oxidative degradation of the intermediates and target molecule was prevented by alkaline hydrolysis of the chlorogenic acids in the presence of sodium dithionite (Na2S2O4) and deprotection of the catecholic diacetate precursor by Candida antarctica lipase B-mediated transesterification as the final step.
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