title: Preparative separation and purification of epigallocatechin gallate from green tea extracts using a silica adsorbent containing β-cyclodextrin.
abstract: A silica adsorbent containing β-cyclodextrin (β-CD) has been developed and used for the separation and purification of epigallocatechin gallate (EGCG) from the green tea extracts. The batch adsorption experiments demonstrated that, the β-CD bonded silica adsorbent possessed excellent adsorption equilibrium capacity (> 55 mg/g adsorbent) and adsorption ratio (>95%) for EGCG compared to the other tea catechins and caffeine. The excellent adsorption capacity and selectivity for EGCG are attributed to the specific interactions between β-CD and EGCG. The preparative separation and purification performance of EGCG on the β-CD bonded silica column (220 mm L × 15 mm i.d., 40-63 μm) was then evaluated. The column was operated in the polar organic mode using methanol/acetonitrile/acetic acid as the mobile phase and eluted under a three-step gradient elution program. The sample was dissolved in acetonitrile and loaded on a preparative scale of about 0.8 mg/g adsorbent. Under the optimal chromatographic conditions, the target compound, EGCG, being the most retained species, was obtained at a purity of about 90% with a recovery of about 90%. The productivity of EGCG was about 6 mg per injection, which can be further increased by scaling-up the chromatographic system.
authors.affiliation: Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin 640, Taiwan. laism@yuntech.edu.tw
authors.forename: Shih-Ming
authors.initials: SM
authors.lastname: Lai
authors.forename: Jhe-Yu
authors.initials: JY
authors.lastname: Gu
authors.forename: Bing-Hao
authors.initials: BH
authors.lastname: Huang
authors.forename: Chieh-Ming J
authors.initials: CM
authors.lastname: Chang
authors.forename: Wen-Lung
authors.initials: WL
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D002110:Caffeine / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D013662:Tea; D047392:beta-Cyclodextrins; D002110:Caffeine; D012822:Silicon Dioxide; D002392:Catechin; C045651:epigallocatechin gallate