Hydroxysteroids detection

An IMER immobilizing 3 a-hydroxysteroid dehydrogenase was employed for HPLC determination of cholic acid and a detection limit of 2 pmol was achieved [44], This approach has the advantage of permitting a repeatable use of the enzyme. 

Kawasaki T, Maeda M, Tsuji A (1983) Immobilized -hydroxysteroid dehydrogenase and dansyl hydrazine as a pre-labeling reagent for high-performance liquid chromatography with fluorescence detection of bile acids. J Chromatogr 272 261-268... 

An enzyme reactor with immobilized 3 -hydroxysteroid dehydrogenase has been successfully used for the analysis of residues of 17 -methyltestosterone in trout by high-performance liquid chromatography (HPLC) (269). Following their separation by reversed-phase chromatography, the major tissue metabolites of 17 -methyltestosterone, namely 5 -androstane-17 -methyl-3, 17 -diol, and 5 -androstane-17 -methyl-3, 17 -diol, were enzymatically modified in the presence of a coreactant, nicotinamide-adenine dinucleotide (NAD), to the corresponding ketone. The position at 3 was enzymatically oxidized, and NADH, the reduced form of NAD, was produced as a coproduct and subjected to fluorescence detection. Reoxidation of NADH to NAD provides the possibility for electrochemical detection. 

The activity A5-3/3-hydroxysteroid dehydrogenase catalyzes the conversion of pregnenolone to progesterone, the progestational hormone of the placenta and corpus luteum. The product has an absorption maximum at 240 nm, and therefore detection can be readily carried out by UV absorbances near this wavelength. 

R. Xu, B.-C. Sang, M. Navre, and D. B. Kassel, Cell-Based Assay Screening lip-Hydroxysteroid Dehydrogenase Inhibitors Using Liquid Chromatography/ Tandem Mass Spectrometry Detection, Rapid Commun. Mass. Spectrom. 20 (2006), 1-5. 

Xu, R. Sang, B.-C. Navre, M. Kassel, D. B. Cell-based assay for screening 1 Ib-hydroxysteroid inhibitors using liquid chromatography/tandem mass spectrometry detection. Rapid Commun. Mass Spectrom. 2006, 20, 1-5. 

The development of analytical assays enabling the comprehensive detection of AAS in sports drug testing samples has required the consideration of the commonly rather extensive metabolism of these xeno-biotics. Principle metabolic reactions of synthetic anabolic steroids are closely related to those reported for testosterone (see section 6.1.2.2), with major pathways controlled by various enzymes such as members of the cytochrome P450 system, 17 3-hydroxysteroid dehydrogenase, 3a-/3P-hydroxysteroid dehydrogenase and 5a-reductases, which are primarily responsible for the conversion of testosterone into active... 

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