Synthesis, clean-up and mass spectrometric characterization of both YK-11 metabolites 5β‐19‐Nor‐pregnane‐3α,17β,20‐triol and 5β‐19‐Nor‐pregnane‐3α,17β‐diol‐20‐one

Code: 241A04MT

Already in 2006 the synthesis of (17α,20E)‐17,20‐[(1‐methoxyethylidene) bis (oxy)]‐3‐oxo‐19‐norpregna‐4,20‐diene‐21‐carboxylic acid methyl ester (YK-11) was published and investigations into its pharmacological properties demonstrated the potential of YK-11 as a selective androgen receptor modulator (SARM). Albeit YK-11 has not been approved for humans until now, it was first detected in a black-market product in 2017 and several times thereafter. According to the Dietary Supplement Label Database issued by the National Institutes of Health, at least 6 different preparations are currently available in the United States alone claiming to contain YK-11.

In 2018 the human metabolism of YK-11 was investigated and two main urinary metabolites were detected suitable to be implemented into routine doping control procedures. YK-11 itself was not detected in urine, presumably due to the fact that it undergoes fast metabolism in humans. As the parent compound YK-11 will not be found in urine after administration, doping controls can only rely on the identified urinary metabolites. Both metabolites were synthesized in order to elucidate their chemical structure, but no reference material at a larger scale was synthesized at that time suitable to be provided to all doping control laboratories worldwide.

In order to enable all laboratories to implement the urinary metabolites of YK-11 into their screening procedures, the production of a suitable reference material of both YK-11 metabolites will be inevitable. Therefore, the aim of this research project is to reinvestigate the different potential routes of chemical synthesis, optimize these and produce reference material of both YK-11 metabolites in order to distribute this to all accredited doping control laboratories.