Synthetic Peptides in Doping Control: A Powerful Tool for an Analytical Challenge

Abstract

Peptides are very diverse molecules that can participate in a wide variety of biological processes. In this way, peptides are attractive for doping, since these molecules can activate or trigger biological processes that can improve the sports performance of athletes. Peptide molecules are found in the official World Anti-Doping Agency lists, mainly in sections S2, S4, and S5. In most cases, these molecules have a very short half-life in the body and/or are identical to natural molecules in the body, making it difficult to analyze them as performance-enhancing drugs. This article reviews the role of peptides in doping, with special emphasis on the peptides used as reference materials, the pretreatment of samples in biological matrices, the instrumentation, and the validation of analytical methodologies for the analysis of peptides used in doping. The growing need to characterize and quantify these molecules, especially in complex biological matrices, has generated the need to search for robust strategies that allow for obtaining sensitive and conclusive results. In this sense, strategies such as solid phase peptide synthesis (SPPS), seeking to obtain specific peptides, metabolites, or isotopically labeled analogs, is a key tool for adequate quantification of different peptide molecules in biological matrices. This, together with the use of optimal methodologies for sample pretreatment (e.g., SPE or protein precipitation), and for subsequent analysis by high-resolution techniques (mainly hyphenated LC-HRMS techniques), have become the preferred instrumentation to meet the analytical challenge involved in the analysis of peptides in complex matrices.

Synthesis and characterization of octopamine sulfate, norfenefrine sulfate and etilefrine sulfate reference materials for doping control

“…Finally, after benzylic hydroxyl and amine group deprotection, the desired sulfate conjugated metabolites would be afforded. 9,[36][37][38]41,43,[47][48][49][50] To validate our hypothesis, we began the synthesis of OS (4) from octopamine hydrochloride (1). As shown in Scheme 1, initially, tert-butyloxycarbonyl (Boc) protection of the amine group of 1 was carried out to get compound 7 in 98% yield.…”

“…34 Consequently, synthesis of drug metabolites as reference materials has emerged as a new research area within synthetic organic chemistry, which bridges the gap between synthetic, medicinal and analytical chemistry. 9,12,[35][36][37]…”

“…Currently, athletes use peptide molecules to improve their athletic performance. 12,13 It is reported in the literature that a high oral dose of these substances has an anabolic or harmful impact. 14 Octopamine, norfenefrine and etilefrine structure are closely related to norepinephrine and were restricted under the S6 stimulants category in 2005-2006 because of performance-amplifying properties.…”

Detection and quantification of the metabolite Ac‐Tβ1–14 in in vitro experiments and urine of rats treated with Ac‐Tβ4: A potential biomarker of Ac‐Tβ4 for doping tests

“…The therapeutic potentials of these drugs are broad and can be used to treat various diseases 1 . In recent years, the development of peptides and their analogs in the pharmaceutical industry was significantly increased 2 . Hundreds of peptide drugs getting approval for diagnosis and treatment in every year are of endogenous sources or derived from natural proteins being widely found in animal, plants, microorganisms, and their by‐products 3,4 .…”

“…1 In recent years, the development of peptides and their analogs in the pharmaceutical industry was significantly increased. 2 Hundreds of peptide drugs getting approval for diagnosis and treatment in every year are of endogenous sources or derived from natural proteins being widely found in animal, plants, microorganisms, and their by-products. 3,4 Researches on synthesis, isolation, and purification technologies of peptides and proteins are also steadily increasing.…”