title: Chiral separation of (+)/(-)-catechin from sulfated and glucuronidated metabolites in human plasma after cocoa consumption.
abstract: Cocoa is well-known to be rich in flavan-3-ols. Previous analyses have established that alkaline treatment of cocoa beans results in epimerization of (-)-epicatechin to (-)-catechin and (+)-catechin to (+)-epicatechin. Now, the question is whether both epimers can be absorbed by the human organism. This paper describes sample preparation and an HPLC method for chiral determination of (+)/(-)-catechin from sulfated and glucuronidated metabolites in human plasma. The sample preparation includes enzymatic hydrolysis of the catechin metabolites, and solid-phase extraction (SPE). A PM-gamma-cyclodextrin column is used with a coulometric electrode-array detection (CEAD) system. The recovery of catechin ranges from 89.9 to 96.8%. The limit of detection is 5.9 ng mL(-1) for (-)-catechin and 6.8 ng mL(-1) for (+)-catechin, and the limit of quantification is 12.8 ng mL(-1) for (-)-catechin and 16.9 ng mL(-1) for (+)-catechin. The relative standard deviation of the method ranges from 0.9 to 1.5%. This method was successfully applied to human plasma after consumption of a cocoa drink. In one human self-experiment, (+)-catechin and (-)-catechin were found in human plasma, but metabolism of the two enantiomers differed.
authors.affiliation: Institute of Nutrition and Food Sciences, University of Bonn, Endenicher Allee 11-13, 53115, Bonn, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Ritter
authors.forename: Benno F
authors.initials: BF
authors.lastname: Zimmermann
authors.forename: Rudolf
authors.initials: R
authors.lastname: Galensa
mesh_terms: D000328:Adult; D001628:Beverages; D002099:Cacao / Q000378:metabolism*; D002392:Catechin / Q000097:blood* / Q000302:isolation & purification* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D052616:Solid Phase Extraction / Q000379:methods; D013237:Stereoisomerism
chemical_list: D002392:Catechin