A new derivative for oxosteroid analysis by mass spectrometry

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Oxosteroids are important biomarkers in various physiological and pathological processes.
• Accurate identification and quantification of oxosteroids are crucial for clinical diagnostics and research.
• Existing methods for oxosteroid analysis can be limited in sensitivity or scope.

Purpose of the Study:

• To develop and validate a novel derivatisation reagent, tandem mass tag hydrazine (TMTH), for oxosteroid identification.
• To enhance the sensitivity and specificity of oxosteroid detection using mass spectrometry.
• To demonstrate the applicability of the TMTH method in complex biological matrices.

Main Methods:

• Synthesis and characterization of the TMTH reagent, featuring a carbonyl-reactive hydrazine group and a charged tertiary amino group.
• Derivatisation of thirty authentic oxosteroids with TMTH.
• Analysis of derivatised oxosteroids using electrospray ionization mass spectrometry (ESI-MS).
• Characterization of fragmentation patterns using ESI-tandem mass spectrometry (MS/MS) to identify specific reporter ions.
• Application of a shotgun ESI-MS method with TMTH derivatisation to a human urine sample.

Main Results:

• TMTH derivatisation significantly increased ion currents for analysed oxosteroids compared to underivatised molecules.
• ESI-MS/MS analysis of TMTH-derivatised oxosteroids produced characteristic fragmentation patterns.
• Specific mass reporter ions derived from the tandem mass tag (TMT) group were observed, facilitating identification.
• The shotgun ESI-MS method incorporating TMTH derivatisation proved effective for analysing oxosteroids in a complex urine sample.

Conclusions:

• Tandem mass tag hydrazine (TMTH) is an effective derivatisation reagent for enhancing oxosteroid detection by mass spectrometry.
• The TMTH method provides characteristic fragmentation patterns and reporter ions, aiding in reliable oxosteroid identification.
• This novel approach offers a sensitive and robust tool for oxosteroid profiling in biological samples, with potential applications in diagnostics and biomarker discovery.