title: Determination of D-serine in human serum by LC-MS/MS using a triazole-bonded column after pre-column derivatization with (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7- (N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole.
abstract: An LC-MS/MS-based method for determining D-serine (Ser), an endogenous co-agonist of the N-methyl-D-aspartate receptor, in human serum, was developed and validated using a triazole-bonded silica-packed column after pre-column fluorescence derivatization with a chiral labeling reagent, (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole. Enantiomeric separation of the D- and L-Ser derivatives occurred in the triazole-bonded column (R s: 1.85) with CH3CN/100 mM HCO2NH4 in H2O (95.5:4.5) as the mobile phase with isocratic elution. The ln(capacity factor of D-Ser) in the van't Hoff plot gradually decreased with the inverse of temperature, suggesting enhanced hydrophilic interactions with the triazole-bonded stationary phase with increasing column temperature, owing to decrease in the partition coefficient to the mobile phase. Multiple reaction monitoring (m/z 457.10 > 409.00) by triple quadrupole mass spectrometry was used for quantifying D-Ser in human serum. The presence of D-Ser in the serum was confirmed by treatment with commercial D-amino acid oxidase. A linear calibration curve was constructed in the D-Ser concentration range of 0.5-5.0 μM (r (2) = 0.999, n = 3) using D-homoserine as the internal standard. The precision and recovery values were adequate for quantification. The detection limit for D-Ser was 1.1 fmol/injection (signal-to-noise ratio = 3), owing to the high CH3CN content in the mobile phase. The proposed LC-MS/MS method showed few fluctuations in the retention times of D- and L-Ser, and R s was stable until the 40th injection of serum without column washing, and thus can be useful for D-Ser determination in human serum in clinical research.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Ryousuke
authors.initials: R
authors.lastname: Kuwabara
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Onozato
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ichiba
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Iizuka
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba, 274-8510, Japan. t-fukushima@phar.toho-u.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukushima
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D017879:Isothiocyanates / Q000737:chemistry; D057230:Limit of Detection; D010069:Oxadiazoles / Q000737:chemistry; D012694:Serine / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: C107817:4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole; D017879:Isothiocyanates; D010069:Oxadiazoles; D012694:Serine
keywords: (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole; D-Amino acid oxidase; D-serine; Human serum; LC-MS/MS