title: A high-performance liquid chromatography assay with a triazole-bonded column for evaluation of d-amino acid oxidase activity.
abstract: Elution profiles of kynurenic acid (KYNA) and 7-chlorokynurenic acid (Cl-KYNA) were examined by high-performance liquid chromatography (HPLC) using a triazole-bonded stationary phase column (Cosmosil® HILIC) under isocratic elution of a mobile phase consisting of CH3 CN-aqueous 10 mm ammonium formate between pH 3.0 and 6.0. The capacity factors of KYNA and Cl-KYNA varied with both the CH3 CN content and the pH of the mobile phase. The elution order of KYNA and Cl-KYNA was reversed between the CH3 CN- and H2 O-rich mobile phases, suggesting that hydrophilic interactions and anion-exchange interactions caused retention of KYNA and Cl-KYNA in the CH3 CN- and H2 O-rich mobile phases, respectively. The present HPLC method using a triazole-bonded column and fluorescence detection (excitation 250 nm, emission 398 nm) was applied to monitor in vitro production of KYNA from d-kynurenine (d-KYN) by d-amino acid oxidase (DAO) using Cl-KYNA as an internal standard. A single KYNA peak was clearly observed after enzymatic reaction of d-KYN with DAO. Production of KYNA from d-KYN was suppressed by the addition of commercial DAO inhibitors. The present HPLC method can be used to evaluate DAO activity and DAO inhibitory effects in candidate drugs for the treatment of schizophrenia.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Iwasaki
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kashiwaguma
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Nagashima
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Mao
authors.initials: M
authors.lastname: Izumi
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Uekusa
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, 274-8510, Japan.
authors.forename: Sumiko
authors.initials: S
authors.lastname: Iwasa
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 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, 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, Chiba, 274-8510, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukushima
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003605:D-Amino-Acid Oxidase / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D007737:Kynurenine / Q000378:metabolism; D014230:Triazoles / Q000737:chemistry*
chemical_list: D014230:Triazoles; D007737:Kynurenine; D003605:D-Amino-Acid Oxidase; D007736:Kynurenic Acid; C057013:7-chlorokynurenic acid
keywords: Cosmosil HILIC®; d-amino acid oxidase; d-kynurenine; kynurenic acid; triazole-bonded stationary phase