title: Determination of thymopentin in beagle dog blood by liquid chromatography with tandem mass spectrometry and its application to a preclinical pharmacokinetic study.
abstract: The pentapeptide thymopentin (Arg-Lys-Asp-Val-Tyr, RKDVY) corresponds to amino acids 32-36 of the 49 amino acid immunomodulatory polypeptide, thymopoietin, whose biological activity is partially reproduced. Thymopentin is widely used in the clinic and represents a promising target for drug design but bioanalytical and pharmacokinetic data are limited due to its enzymatic instability. This paper reports a rapid and sensitive method based on liquid chromatography with tandem mass spectrometry for the determination of thymopentin in beagle dog blood. To inactivate peptidases and stabilize thymopentin, acetonitrile was added to blood samples immediately after collection followed by addition of stable isotope-labeled thymopentin as internal standard and washing with dichloromethane. Chromatography was carried out on an Ascentis Express Peptide ES-C18 column using gradient elution with methanol and aqueous 0.1% formic acid at a flow rate of 0.6 mL/min. Positive electrospray ionization mass spectrometry with selected reaction monitoring achieved linearity in the range of 1.5-800 ng/mL with good accuracy/precision and minimal matrix effects. The method was successfully applied to a pharmacokinetic study in beagle dogs after intravenous administration of 0.2 mg/kg thymopentin.
authors: College of Life Science, Jilin University, Changchun, P. R. China.
authors: Meiyun
authors: M
authors: Shi
authors: Yan
authors: Y
authors: Yang
authors: Xiaotong
authors: X
authors: Zhou
authors: Lanlan
authors: L
authors: Cai
authors: Chunxue
authors: C
authors: Fang
authors: Can
authors: C
authors: Wang
authors: Heping
authors: H
authors: Sun
authors: Yantong
authors: Y
authors: Sun
authors: Yin
authors: Y
authors: Gao
authors: Jingkai
authors: J
authors: Gu
authors: J Paul
authors: JP
authors: Fawcett
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000818:Animals; D002138:Calibration; D002853:Chromatography, Liquid; D004285:Dogs; D016014:Linear Models; D008752:Methylene Chloride / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011786:Quality Control; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D016305:Thymopentin / Q000097:blood*
chemical_list: D000097:Acetonitriles; D010455:Peptides; D008752:Methylene Chloride; D016305:Thymopentin; C032159:acetonitrile
keywords: Dog blood; Liquid chromatography with tandem mass spectrometry; Peptides; Pharmacokinetics; Thymopentin