A rapid and sensitive LC-MS/MS method for quantifying oxycodone, noroxycodone, oxymorphone and noroxymorphone in human plasma to support pharmacokinetic drug interaction studies of oxycodone. | LitMetric
A sensitive and reliable LC-MS/MS method was developed and validated for the quantification of oxycodone and metabolites in human plasma. The method has a runtime of 6 min and a sensitivity of 0.1 μg/L for all analytes. Sample preparation consisted of protein precipitation. Separation was performed on a Kinetix biphenyl column (2.1 × 100 mm, 1.7 μm), using ammonium formate 5 mm in 0.1% aqueous formic acid and methanol LC-MS grade 100% in gradient elution at a flow rate of 0.4 ml/min. Detection was performed in multiple reaction monitoring mode using positive electrospray ionization. The method was linear over the calibration range of 0.1-25.0 μg/L for oxycodone, noroxycodone and noroxymorphone and 0.1-5.0 μg/L for oxymorphone. The method demonstrated good performance in terms of intra- and interday accuracy (86.5-110.3%) and precision (CV 1.7-9.3%). The criteria for the matrix effect were met (CV < 15%) except for noroxymorphone, for which an additional method was applied to compensate for the matrix effect. Whole blood samples were stable for 4 h at room temperature. Plasma samples were stable for 24 h at room temperature and 3 months at -20°C. Furthermore, the method was successfully applied in a pharmacokinetic drug interaction study of oxycodone and enzalutamide in patients with prostate cancer.
Introduction: Protein acetylation is an extensively investigated post-translational modification (PTM). In addition to lysine acetylation, three new types of lysine acylations characterized by the presence of an acidic carboxylic group have been recently identified and validated. These included lysine malonylation (Kmal), lysine succinylation (Ksucc) and lysine glutarylation (Kglu).
Proteomics, Lipidomics and Metabolomics Core Facility, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia.
Introduction: The identification of effective, selective biomarkers and therapeutics is dependent on truly deep, comprehensive analysis of proteomes at the proteoform level.
Methods: Bovine serum albumin (BSA) isolated by two different protocols, cold ethanol fractionation and heat shock fractionation, was resolved and identified using Integrative Top-down Proteomics, the tight coupling of two-dimensional gel electrophoresis (2DE) with liquid chromatography and tandem mass spectrometry (LC-MS/MS).
Results And Discussion: Numerous proteoforms were identified in both "purified" samples, across a broad range of isoelectric points and molecular weights.
Background: Glioblastoma (GB) is the stage IV of glioma and mesenchymal GB represents the most common and malignant subtype characterized with elevated expression of a mesenchymal marker YKL-40 and resistance to immune drug therapy. Here, we determined if YKL-40 regulates kynurenine (Kyn) pathway (KP) metabolism that contributes to establishing an immune suppressive microenvironment in GB.
Methods: Tumor cells expressing YKL-40 from GB patients were isolated and activated cellular metabolisms were identified via gene microarray analysis.
A previously developed algorithm for the preliminary identification of protein proteoforms associated with post-translational modifications (PTMs) based on 2D electrophoresis data (DOI: 10.18097/BMCRM00191) has been used in this study for analysis of experimental data obtained using mice and reported in two papers by different authors. The authors of the first paper identified 8 groups of spots on 2D electrophoretic maps corresponding to 8 proteins with at least two unconcretised proteoforms.
Objective: Glucose metabolism is the main way in which cells obtain energy during exercise and plays an important role in exercise. The purpose of this study was to explore the changes in the expression of glucose metabolism-related proteins in urine after running, and finally applied to the monitoring of running training.
Methods: Urine samples were collected before and after running, and urine proteomics information was collected to explore the expression of proteins in the urine using LC-MS/MS in DDA mode and DIA mode.
