17-Ketosteroid conjugates

The steroid moiety can be detected once again with sulphuric acid or, for 17-ketosteroid conjugates, with m-dinitrobenzene for example. The acid component can be characterised by either the Folin-Ciocalteu reagent (No. 122) or pyridylazonaphthol reagent (No. 215) for glucuronides and methylene blue (Rgt. No. 162) for sulphates [44]. 

Effective Adsorption of Dehydroepi-androsterone (DHA) Sulfate and Other 17-Ketosteroid Conjugates from Urine by Amberlite Clin. Biochem. 4(4) 287-296 (1971) ... 

In summary, the hydrolysis of urinary 17-ketosteroid conjugates may be achieved under a variety of conditions of acid concentration, temperature, and time. Using the criterion of total yields of 17-ketOBteroids, those methods which employ refluxing of the urine, made approximately 1.6 N in acid, for 10 to 30 minutes can be considered satisfactory. 

A"" -3-Ketones are more reactive than cross-conjugated A ""-3-ketones. A"" -3,3-CycIoethylenedioxy compounds can be easily prepared by acid-catalyzed reaction with ethylene glycol or by exchange dioxolanation. 3,3-Cycloethylenedioxy-A -dienes can be prepared from 3,3-cycloethy-lenedioxy-A -enes by allylic bromination and dehydrobromination. Acid hydrolysis yields A"" -3-ketosteroids. ... 

The catabolism of plasma testosterone and other androgens occurs primarily in the liver (Fig. 63.3), where they are conjugated into water-soluble compounds that are excreted by the kidney as the urinary 17-ketosteroids. 

Condensation of isoniazid (isonicotinic acid hydrazide) with any a" -3-ketosteroid in acidic medium affords a yellow color conjugate, allowing the determination of 10-40 pg of the steroid [73]. The reagent is prepared by dissolving 0.8 g of isoniazid in 100 mL of methanol containing 1 mL of concentrated HCl, and then 12.5 mL of this solution is further diluted to 100 mL with methanol. To a 2 mL methanolic sample solution of the 3-ketosteroid is added 2 mL of the reagent. The mixture is allowed to stand at room temperature for an hour, and then the absorbance of the resulting colored solution is measured at 380 nm. In a 1 cm spectrophotometer cell, an absorbance of 0.3 will be produced by 42 pg of cortisone, 34 pg of prednisolone, 29 pg of prednisone, or 32.5 pg of dexamethasone [72]. 

VandenHeuvel and Horning [379] dealt with the preparation of dimethylhydrazones of ketosteroids an oxo group in position 3, non-conjugated with a double bond, reacts with dimethylhydrazine alone. The preparation of hydrazones in positions 16, 17 and 20 and 3 conjugated with a double bond requires acid catalysis the 11-keto group does not react. SE-30 or QF-1 (1%) were satisfactory stationary phases. Condensation with other reagents and preparation of substituted hydrazones can serve for the characterization and identification of ketosteroids [380]. 

Bordoloi, M. Cadmium chloride-magnesium-water a new system for regioselective transformation of conjugated nitroalkenes to ketocompounds conversion of 6-nitro-D5-steroids to 6-ketosteroids. J. Chem. Soc., Chem. Commun. 1993, 922-923. 

The main excretory metabohtes of androstenedione, testosterone, and DHEA are shown in Figure 53-5. Except for epitestosterone, these catabolites constitute a group of steroids known as 17-ketosteroids (17-KSs). These metabolites are excreted primarily in the urine (>90%), with approximately half as 17-KSs, and half as diols, triols, conjugates, and other polar compounds." ... 

Bromination [1, 960, after citation of ref. 16]. Perelman et /.16a found that 19-nor-A, 0 -3-ketosteroids (1) are converted in one step into conjugated 19-nor-A4,9-... 

The unhindered, disubstituted conjugated 1,2-double bond of a A -3-ketosteroid (a) was reduced readily, but /S,j8-disubstituted conjugated ketones (b) proved unreactive under the same conditions. 

B3. Baulieu, E. E., Studies of conjugated 17-ketosteroids in a case of adrenal tumor. J. Clin. Endocrinol. 22, 501-510 (1962). 

Conrad, S., Mahesh, V., and Herrmann, W., Quantitative paper chromatography of conjugated 17-ketosteroids in plasma. J. Clin. Invest. 40, 947-935 (1961). 

Enol acetylation. Enol acetylation of steroidal ketones with acetic anhydride catalyzed by perchloric acid has been shown to be thermodynamically controlled (2,309). However, this acetylating reagent in the case of conjugated ketones gives complex mixtures of O-acylated and C-acylated products.1 Dienone-phenol rearrangements have been noted with A4-3-ketosteroids alkylated at C2 or C6.2... 

Oxo-A -ketosteroid isomerase (KSI), that catalyzes the cofactor-independent tautomeric interconversion of the a,j8- and j8,y-unsaturated 3-oxo-steroids via a dieno-late anion intermediate, has received considerable recent mechanistic and structural scrutiny by Pollack and Mildvan and their coworkers. The reaction catalyzed by KSI is arguably simpler than that catalyzed by TIM the value of the pKa of the unconjugated 5-androstene-3,17-dione is 12.7 whereas that of the conjugated... 

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