Determination of l‐tryptophan and l‐kynurenine derivatized with (R)‐4‐(3‐isothiocyanatopyrrolidin‐1‐yl)‐7‐(N, N‐dimethylaminosulfonyl)‐2, 1, 3‐benzoxadiazole by LC‐MS/MS on a triazole‐bonded column and their quantification in human serum. (14th March 2016)

• Record Type: Journal Article
• Authors: Takahashi, Shuuhei; Iizuka, Hideaki; Kuwabara, Ryousuke; Naito, Yoko; Sakamoto, Tatsuya; Miyagi, Aya; Onozato, Mayu; Ichiba, Hideaki; Fukushima, Takeshi
• Is Part Of: Biomedical chromatography. Volume 30:Number 9(2016:Sep.)
• Page Start: 1481
• Page End: 1486
• Publication Date: 2016-03-14
• Subjects: Chromatographic analysis -- Periodicals; Biology -- Periodicals; Medicine -- Periodicals; Biology -- Periodicals; Chromatography -- methods -- Periodicals; Medicine -- Periodicals; 543.089
• DOI: 10.1002/bmc.3709
• Languages: English
• ISSNs: 0269-3879

Abstract

Abstract: The concentrations ofl ‐tryptophan (Trp) and the metabolitel ‐kynurenine (KYN) can be used to evaluate the in‐vivo activity of indoleamine 2, 3‐dioxygenase (IDO) and tryptophan 2, 3‐dioxygenase (TDO). As such, a novel method involving derivatization ofl ‐Trp andl ‐KYN with ( R )‐4‐(3‐isothiocyanatopyrrolidin‐1‐yl)‐7‐( N, N ‐dimethylaminosulfonyl)‐2, 1, 3‐benzoxadiazole (DBD‐PyNCS) and separation by high‐performance liquid chromatography (HPLC) with tandem mass spectrometric (MS/MS) detection on a triazole‐bonded column (Cosmosil HILIC®) was developed to determine their concentrations. The optimized mobile phase, CH3 CN/10 mm ammonium formate in H2 O (pH 5.0) (90:10, v/v) eluted isocratically, resulted in satisfactory separation and MS/MS detection of the analytes. The detection limits ofl ‐Trp andl ‐KYN were approximately 50 and 4.0 pm, respectively. The column temperature affected the retention behaviour of the Trp and KYN derivatives, with increased column temperatures leading to increased capacity factors; positive enthalpy changes were revealed by van't Hoff plot analyses. Using the proposed LC‐MS/MS method, l ‐Trp andl ‐KYN were successfully determined in 10 μL human serum using 1‐methyl‐l ‐Trp as an internal standard. The precision and recovery ofl ‐Trp were in the ranges 2.85–9.29 and 95.8–113%, respectively, while those ofl ‐KYN were 2.51–16.0 and 80.8–98.2%, respectively. The proposed LC‐MS/MS method will be useful for evaluating the in vivo activity of IDO or TDO. Copyright © 2016 John Wiley & Sons, Ltd.