Identification and synthesis of (Z)-3'-hydroxy clomiphene as a new potential doping-relevant metabolite of clomiphene.

Abstract

(E/Z)-3'-HC and (E/Z)-4'-HC were synthesized involving the McMurry reaction. An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and optimized after a derivatization step with dansyl chloride to separate eight HC isomers. Using this method, urine samples from a controlled clomiphene administration study were analyzed, in which male study participants received therapeutic doses of clomiphene for 30 days and collected urine samples for up to 8months. Thus, isomer-specific HC elimination profiles could be monitored. The metabolite previously found in doping-control samples was identified as (Z)-3'-HC. The elimination profiles of the different HCs confirmed previous results, with (Z)-3-HC being the most abundant urinary hydroxy metabolite shortly after administration. A new finding was that the data suggest that (Z)-3'-HC is excreted at higher relative concentrations only several weeks after drug intake. These findings might be of particular importance in sport drug testing as they can assist in the decision-making process to distinguish between intentional doping and inadvertent exposure to clomiphene via food contamination.