title: A novel chemoenzymatic synthesis of propyl caffeate using lipase-catalyzed transesterification in ionic liquid.
abstract: Propyl caffeate has the highest antioxidant capacity in the caffeate alkyl esters family, but industrial production of propyl caffeate is hindered by low yields using either the chemical or enzymatic catalysis method. To set up a high-yield process for obtaining propyl caffeate, a novel chemoenzymatic synthesis method using lipase-catalyzed transesterification of an intermediate methyl caffeate or ethyl caffeate and 1-propanol in ionic liquid was established. The maximum propyl caffeate yield of 98.5% was obtained using lipase-catalyzed transesterification under the following optimal conditions: Novozym 435 as a biocatalyst, [Bmim][CF3SO3] as a medium, a molar ratio of methyl caffeate to 1-propanol of 1:5, a mass ratio of methyl caffeate to lipase of 1:20, and a reaction temperature of 60°C. The two-step conversion of caffeic acid to propyl caffeate via methyl caffeate is an efficient way to prepare propyl caffeate with an overall yield of 82.7%.
authors.affiliation: School of Biology and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Pang
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Gu
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Hong-Sheng
authors.initials: HS
authors.lastname: Cui
authors.forename: Fang-Qin
authors.initials: FQ
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Xing-Yu
authors.initials: XY
authors.lastname: Zhao
authors.forename: Fu-An
authors.initials: FA
authors.lastname: Wu
mesh_terms: D000433:1-Propanol / Q000378:metabolism; D055162:Biocatalysis / Q000187:drug effects; D002109:Caffeic Acids / Q000138:chemical synthesis* / Q000378:metabolism; D004951:Esterification / Q000187:drug effects; D052578:Ionic Liquids / Q000494:pharmacology*; D008049:Lipase / Q000378:metabolism*; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature
chemical_list: D002109:Caffeic Acids; D052578:Ionic Liquids; C042405:methyl caffeate; C032773:ethyl caffeate; D000433:1-Propanol; D008049:Lipase