Owing to the developments of analytical instruments and interfaces (e.g. coupling high-performance liquid chromatography to mass spectrometry), there has been increased interest in new reference materials, for example in doping analysis with steroid glucuronide conjugates. The synthesized reference material has to pass several characterization steps including the use of gas chromatography/mass spectrometry (GC/MS) for its structure confirmation. In the present study, the fragmentation and mass spectrometric behaviour of several steroid glucuronide conjugates of endogenous and anabolic steroids after derivatization to pertrimethylsilylated products and to methyl ester pertrimethylsilylated products were investigated using GC/MS ion trap and GC/MS quadrupole instruments. The mass spectra of the derivatives of androsterone glucuronide, d5-androsterone glucuronide, epiandrosterone glucuronide, etiocholanolone glucuronide, 11beta-hydroxy etiocholanolone glucuronide, 19-norandrosterone glucuronide, d4-19-norandrosterone glucuronide and 1alpha-methyl-5alpha-androstan-3alpha-ol-17-one glucuronide are presented and the origin of typical fragment ions of the glycosidic and steroidal moieties is proposed, based on different derivatization techniques including derivatization with d18-bistrimethylsilylacetamide, methyl ester and trimethylsilyl ester derivatization and selected reaction monitoring. Typical fragmentation patterns which are related to the steroid structure are discussed.
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http://dx.doi.org/10.1002/jms.117 | DOI Listing |
Front Pharmacol
January 2025
Department of Clinical Pharmacology and Toxicology, Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
Background: Dabigatran etexilate (DABE), a prodrug of dabigatran (DAB), is a direct thrombin inhibitor used to prevent ischemic stroke and thromboembolism during atrial fibrillation. The effect of genetic polymorphisms on its metabolism, particularly , has not been extensively explored in humans. This study aimed to investigate the effects of , , and polymorphisms on the pharmacokinetics of DAB and its acylglucuronide metabolites in healthy subjects.
View Article and Find Full Text PDFJ Pharm Anal
October 2024
National Key Laboratory of Chinese Medicine Modernization, State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China.
Identifying the compound formulae-related xenobiotics in bio-samples is full of challenges. Conventional strategies always exhibit the insufficiencies in overall coverage, analytical efficiency, and degree of automation, and the results highly rely on the personal knowledge and experience. The goal of this work was to establish a software-aided approach, by integrating ultra-high performance liquid chromatography/ion-mobility quadrupole time-of-flight mass spectrometry (UHPLC/IM-QTOF-MS) and in-house high-definition MS library, to enhance the identification of prototypes and metabolites of the compound formulae , taking Sishen formula (SSF) as a template.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
January 2025
Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Context: The timing of a woman's final menstrual period (FMP) in relation to her age is considered a valuable indicator of overall health, being associated with cardiovascular, bone health, reproductive, and general mortality outcomes.
Objective: This work aimed to evaluate the relationship between hormones and the "time to FMP" when daily hormone trajectories are characterized by their 1) entropy, and 2) deviation from premenopausal/stable cycle patterns (representing a textbook "gold standard"; GS).
Methods: As part of the Study of Women's Health Across the Nation, urinary luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrogen conjugates (E1C), and pregnanediol glucuronide (PDG) were measured daily from a multiracial sample of 549 mid-life women for the duration of one menstrual cycle.
Pediatr Rep
January 2025
Department of Pediatrics, Division of Pediatric Critical Care Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands.
Objectives: Intravenous midazolam is widely used for sedation in critically ill children. Sometimes, these children develop a paediatric delirium (PD). Our aim was to determine the relationship between midazolam serum concentration and the development of new PD in critically ill children.
View Article and Find Full Text PDFFront Pharmacol
January 2025
State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China.
Introduction: Deglycosylated azithromycin (Deg-AZM), a new transgelin agonist with positive therapeutic effects on slow transit constipation, has been approved for clinical trials in 2024. This work investigated the drug metabolism and transport of Deg-AZM to provide research data for further development of Deg-AZM.
Methods: A combination of UPLC-QTOF-MS was used to obtain metabolite spectra of Deg-AZM in plasma, urine, feces and bile.
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