title: Separation and purification of epigallocatechin-3-gallate (EGCG) from green tea using combined macroporous resin and polyamide column chromatography.
abstract: Epigallocatechin-3-gallate (EGCG) is a major bioactive ingredient of green tea that produces beneficial neuroprotective effects. In this paper, to optimize the EGCG enrichment, thirteen macroporous resins with different chemical and physical properties were systemically evaluated. Among the thirteen tested resins, the H-bond resin HPD826 exhibited best adsorption/desorption capabilities and desorption ratio, as well as weakest affinity for caffeine. The absorption of EGCG on the HPD826 resin followed the pseudo-second-order kinetics and Langmuir isotherm model. The separation parameters of EGCG were optimized by dynamic adsorption/desorption experiments with the HPD826 resin column. Under the optimal condition, the content of EGCG in the 30% ethanol eluent increased by 5.8-fold from 7.7% to 44.6%, with the recovery yield of 72.1%. After further purification on a polyamide column, EGCG with 74.8% purity was obtained in the 40-50% ethanol fraction with a recovery rate of 88.4%. In addition, EGCG with 95.1% purity could be easily obtained after one-step crystallization in distilled water. Our study suggests that the combined macroporous resin and polyamide column chromatography is a simple method for large-scale separation and purification of EGCG from natural plants for food and pharmaceutical applications.
authors: School of Pharmacy, China Medical University, Shenyang 110001, China.
authors: Xin
authors: X
authors: Jin
authors: School of Pharmacy, China Medical University, Shenyang 110001, China.
authors: Mingyan
authors: M
authors: Liu
authors: School of Pharmacy, China Medical University, Shenyang 110001, China.
authors: Zaixing
authors: Z
authors: Chen
authors: School of Pharmacy, China Medical University, Shenyang 110001, China.
authors: Ruikun
authors: R
authors: Mao
authors: School of Pharmacy, China Medical University, Shenyang 110001, China.
authors: Qinghuan
authors: Q
authors: Xiao
authors: School of Pharmacy, China Medical University, Shenyang 110001, China; Division of Pharmacology Laboratory, National Institutes for Food and Drug Control, Beijing 100050, China. Electronic address: huag55@163.com.
authors: Hua
authors: H
authors: Gao
authors: School of Pharmacy, China Medical University, Shenyang 110001, China. Electronic address: minjie_wei@163.com.
authors: Minjie
authors: M
authors: Wei
mesh_terms: D000327:Adsorption; D002392:Catechin / Q000031:analogs & derivatives* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007700:Kinetics; D009757:Nylons / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D009757:Nylons; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate
keywords: Combined column chromatography; Epigallocatechin-3-gallate; Green tea; Macroporous resin; Polyamide