Intact phase II steroid metabolites have poor product ion mass spectra under collision-induced dissociation (CID) conditions. Therefore, we present herein the liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/(MS)) behavior of intact phase II metabolites of oxosteroids after derivatization. Based on the fact that Girard's reagent T (GRT), as derivatization reagent, was both convenient and efficient in terms of the enhancement in the ionization efficiency and the production of diagnostic product ions related to the steroid moiety, the latter was preferably selected between methoxamine and hydroxylamine upon the model compounds of androsterone glucuronide and androsterone sulfate. Sixteen different glucuronides and 29 sulfate conjugated metabolites of anabolic androgenic steroids (AASs), available either as pure reference materials or synthesized/extracted from administration studies, were derivatized with GRT, and their product ion spectra are presented. Product ion spectra include in all cases high number of product ions that in some cases are characteristic for certain structures of the steroid backbone. More specifically, preliminary results have shown major differences in fragmentation pattern for 17α/17β-isomers of the sulfate conjugates, but limited differentiation for 17α/17β-isomers of glucuronide conjugates and for 3α/3β- and 5α/5β-stereoisomers of both sulfate and glucuronide conjugates. Further to the suggestion of the current work, application on mesterolone administration studies confirmed-according to the World Anti-Doping Agency (WADA) TD2015IDCR-the presence of seven intact phase II metabolites, one glucuronide and six sulfates with use of LC-ESI-MS/(MS).

Download full-text PDF

Source
http://dx.doi.org/10.1002/dta.3056DOI Listing

Publication Analysis

Top Keywords

intact phase
16
phase metabolites
12
product ion
12
girard's reagent
8
product ions
8
administration studies
8
ion spectra
8
glucuronide conjugates
8
metabolites
5
product
5

Similar Publications

Gait Analysis in Patients After Hemiepiphysiodesis Due to Valgus or Varus Knee Deformity.

J Clin Med

January 2025

Department of Orthopaedic and Trauma Surgery, Institute of Medical Sciences, University of Opole, 45-040 Opole, Poland.

Developmental knee joint deformities are a common problem in pediatric orthopedics. Children with a valgus or varus deformity of the distal femur or the proximal tibia are commonly treated with hemiepiphysiodesis. Gait analysis in patients with lower limb deformities plays an important role in clinical practice.

View Article and Find Full Text PDF

The regeneration of endothelial cells (ECs) lining arteries, veins, and large lymphatic vessels plays an important role in vascular pathology. To understand the mechanisms of atherogenesis, it is important to determine what happens during endothelial regeneration. A comparison of these processes in the above-mentioned vessels reveals both similarities and some significant differences.

View Article and Find Full Text PDF

Phase separation of specific proteins into liquid-like condensates is a key mechanism for forming membrane-less organelles, which organize diverse cellular processes in space and time. These protein condensates hold immense potential as biomaterials capable of containing specific sets of biomolecules with high densities and dynamic liquid properties. Despite their appeal, methods to manipulate protein condensate materials remain largely unexplored.

View Article and Find Full Text PDF

Reproduction control in a feral feline population using an anti-GnRH vaccine.

Theriogenology

January 2025

Instituto de Investigaciones en Reproducción Animal, FCV, UNLP, Calle 60 y 118, La Plata, B1900AVW, Buenos Aires, Argentina; Universidad del Chaco Austral, Argentina. Electronic address:

This study aimed to evaluate the use of the Improvac® vaccine to avoid heat and pregnancies in queens and fertility in males during the breeding season. Twenty-eight intact animals were divided into treated males (G1, n = 7), treated females (G2, n = 18), and untreated males (G3, n = 3) that were untamed and could not be captured for immunization. In cats from the G1 group, the testicular volume (337.

View Article and Find Full Text PDF

SN514 is a thermolysin-like enzyme under development as a debrider. Preclinical and non-clinical studies supported a first in human healthy volunteer study to predict the need for protection of periwound skin. Pharmacologic activity testing compared digestion of collagen, fibrin, and elastin with relevant enzymes.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!