Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential.

This study identifies a specific fragment of thymosin beta 4 in TB-500 and suggests methods for its detection, but does not provide evidence of its effects or clinical significance.

Summary and findings

This study focuses on the detection and identification of the N-terminal acetylated 17-23 fragment of human thymosin beta 4 (Ac-LKKTETQ) in the peptide formulation TB-500, suspected of doping potential. The identification was achieved using high-performance liquid chromatography and high-resolution mass spectrometry. Additionally, the synthesis of Ac-LKKTETQ was performed through solid-phase peptide synthesis.

Abstract

The formulation TB-500 is suspected to be used as doping agent in sport. This work describes the detection and the identification of the N-terminal acetylated 17-23 fragment of human thymosin beta 4 (Ac-LKKTETQ) in TB-500 by means of high-performance liquid chromatography/high resolution mass spectrometry using an Orbitrap Exactive benchtop mass spectrometer. Ac-LKKTETQ was also synthesized by solid-phase peptide synthesis, and an analytical strategy for detection in plasma and urine by high-performance liquid chromatography/low resolution triple-quadrupole mass spectrometry was suggested.

Key findings

• Not reported in abstract.

Limitations

• Not reported in abstract.

Elsewhere in the TB-500 (Thymosin Beta-4 Fragment) corpus