The preparation of three fluorescence-labelled derivatives of testosterone

Abstract Three fluorescence-labelled derivatives of testosterone were prepared consisting of the steroid separated from the fluorochrome by a hydrocarbon “bridge”. “Bridges” of different lengths (C2 to C7) were used as the length required to avoid steric hindrance effects by the fluorochrome in studies on steroid-protein binding was unknown. The three derivatives prepared were: 17β-hydroxy-4-androsten-3-one 3-(O-(N-(2'mercapto) ethyl)carbamoylmethyl)oxime, 17β-hydroxy-4-androsten-3-one 3-(O-(N-(3'-amino)propyl)carbamoylmethyl)oxime and 17β-hydroxy-4-androsten-3-one 3-(O-(N-(7'-amino)heptyl)carbamoylmethyl)oxime. These were then coupled with either a dansyl or a fluorescein molecule. Overall yields were sufficient and the products immunoreactive with anti-testosterone antiserum.