Synthesis of multiply deuterated 3- and 21-monosulfates of allo-tetrahydrocorticosteroids as internal standards for mass spectrometry.

The accurate analysis of trace components in complex biological matrices requires the use of reliable internal standards. For liquid chromatography/mass spectrometry analysis, the stable isotope-labeled analogues of the analyte molecules are the most appropriate internal standards. In this paper the synthesis of the 3- and 21-monosulfates of allo-tetrahydrocorticosteroids labeled with four or five deuterium atoms is described. The principal reactions used were (1) hydrogen-deuterium exchange reaction of active methylene groups adjacent to 3- and 11-oxo group of 17,20;20,21-bismethylenedioxy derivatives of 5α-3-ketosteroids and/or 5α-11-ketosteroids with NaOD in CH(3)OD followed by reduction with NaBD(4), (2) epimerization of the 3ß-hydroxy group into a 3α configuration, (3) sulfation of hydroxy groups at C-3 or C-21 in the resulting substrates with sulfur trioxide-trimethylamine complex, and (4) removal of 17,20;20,21-bismethylenedioxy groups with hydrogen fluoride in ethanol. Isotopic purity was found to be satisfactory by MS, and NMR properties of the new compounds were tabulated. The labeled compounds can be used as internal standards in liquid chromatography/mass spectrometry assays for clinical and biochemical studies.

Synthesis of 3- and 21-monosulfates of [2,2,3ß,4,4-²H5]-tetrahydrocorticosteroids in the 5ß-series as internal standards for mass spectrometry.

The 3- and 21-monosulfates of pentadeuterated 5ß-tetrahydrocorticosteroides were synthesized, starting from cortisol and 11-deoxycotisol. The principal reactions used were (1) perdeuteration of the methylene groups adjacent to the 3-oxo group of 17,20:20,21-bismethylendioxy-5ß-3-ketosteroids with NaOD in CH(3)OD followed by stereoselective reduction with NaBD(4), (2) sulfation of hydroxy groups with sulfur trioxide-trimethylamine complex, and (3) removal of the 17,20:20,21-bismethylendioxy group with hydrogen fluoride. The labeled compounds can be used as internal standards in liquid chromatography/mass spectrometry assays for clinical and biochemical studies.