title: Quantification of L-ergothioneine in human plasma and erythrocytes by liquid chromatography-tandem mass spectrometry.
abstract: A sensitive analytical method has been developed and validated for the quantification of L-ergothioneine in human plasma and erythrocytes by liquid chromatography-tandem mass spectrometry. A commercially available isotope-labeled L-ergothioneine-d9 is used as the internal standard. A simple protein precipitation with acetonitrile is utilized for bio-sample preparation prior to analysis. Chromatographic separation of L-ergothioneine is conducted using gradient elution on Alltime C18 (150 mm × 2.1 mm, 5 µ). The run time is 6 min at a constant flow rate of 0.45 ml/min. The mass spectrometer is operated under a positive electrospray ionization condition with multiple reaction monitoring mode. The mass transitions of L-ergothioneine and L-ergothioneine-d9 are m/z 230 > 127 and m/z 239 > 127, respectively. Excellent linearity [coefficient of determination (r(2)) ≥ 0.9998] can be achieved for L-ergothioneine quantification at the ranges of 10 to 10,000 ng/ml, with the intra-day and inter-day precisions at 0.9-3.9% and 1.3-5.7%, respectively, and the accuracies for all quality control samples between 94.5 and 101.0%. This validated analytical method is suitable for pharmacokinetic monitoring of L-ergothioneine in human and erythrocytes. Based on the determination of bio-samples from five healthy subjects, the mean concentrations of L-ergothioneine in plasma and erythrocytes are 107.4 ± 20.5 ng/ml and 1285.0 ± 1363.0 ng/ml, respectively.
authors.affiliation: Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore. csiwl@nus.edu.sg
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Wang
authors.forename: Win-Lwin
authors.initials: WL
authors.lastname: Thuya
authors.forename: Dorothy Su-Lin
authors.initials: DS
authors.lastname: Toh
authors.forename: Michael George-Limenta
authors.initials: MG
authors.lastname: Lie
authors.forename: Jie-Ying Amelia
authors.initials: JY
authors.lastname: Lau
authors.forename: Li-Ren
authors.initials: LR
authors.lastname: Kong
authors.forename: Seow-Ching
authors.initials: SC
authors.lastname: Wan
authors.forename: Kian-Ngiap
authors.initials: KN
authors.lastname: Chua
authors.forename: Edmund Jon-Deoon
authors.initials: EJ
authors.lastname: Lee
authors.forename: Boon-Cher
authors.initials: BC
authors.lastname: Goh
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004880:Ergothioneine / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D004912:Erythrocytes / Q000737:chemistry; D006801:Humans; D016014:Linear Models; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000975:Antioxidants; D004880:Ergothioneine