Zimmermann reaction

Note The derivatized steroids can be extracted from the blue chromatogram zones with alcohol and quantitatively determined by means of the Zimmermann reaction, which is not interfered with by the presence of phosphoric acid and phosphomolybdic acid. A yellow background can be bleached by exposure to anunonia vapor [2]. 

ZIMMERMANN REACTION. The reaction that occurs between methylene ketones and aromatic polynitro compounds in the presence of alkali. When applied to 17-oxosleroids, the colored compounds formed can be used for the quantitative determination of 17-oxosteroids. 

In the third example, dehydroepiandrosterone is widely used for standardizing and for checking the performance of the Zimmermann reaction, which forms the final step in many methods of steroid estimation. There is, however, no suitable standard preparation including the commoner urinary steroids and their metabolites which can be carried through all the previous stages of analysis, and the only satisfactory form of standard material that includes the naturally occurring conjugates of the main steroids and their metabolites is urine collected from normal individuals or from patients treated with cortisol. 

B15. BirchaU, K., and Mitchell, F. L., Investigation of the Zimmermann reaction when used for the assay of groups of steroids in infants. Clin. Ckim. Acta 12, 125-136 (1965). 

This reaction is related to the Meisenheimer Complexes and Zimmermann Reaction. 

Ziegler Method Ziegler-Natta Polymerization Zimmermann Reaction Zincke Disulfide Cleavage Zincke Nitration Zincke-Suhl Reaction... 

Such corrections are used in the determination of steroids by the Zimmermann reaction and in the spectrophotometric determination of porphyrins, salicylates and other compounds. Care must be taken whenever it is applied as it is possible that even larger errors might be introduced than there would be without the correction, e.g. when the absorbance of the background is not linear in the region measured. 

Oxogenic steroids. These are urinary corticosteroids and their metabolites, measured by the Zimmermann reaction after borohydride reduction and bismuthate (or periodate) oxidation. Substances measured by this technique are similar to those measured by the Porter-Silber method with the addition of cortol and cortolone. 

An androgenic steroid synthesized in the ovaries, testes and adrenals. It is an intermediate in the synthesis oif testosterone. Together with androstenedione, it constitutes one of the main androgens secreted by the adrenal cortex. It is one of the 17-oxosteroids which can be measured by the Zimmermann reaction. 

This is a collective term for a group of corticosteroids which includes cortisol, cortisone, 11-deoxycortisol and their tetrahydro derivatives which are measured in plasma and urine by the Porter-Silber reaction. The term 17-hydroxysteroids is often used synonymously with 17-oxogenic steroids and to most intents and purposes they mean the same. However there is a subtle difference between the two in that 17-oxogenic steroids (determined by the Zimmermann reaction after reduction and oxidation) measures, in addition to the compounds mentioned above, cortol and cortolone. 

Step in their determination consists of borohydride reduction, by which the corticosteroids and their metabolites are converted to their dihydroxy derivatives. At the same time, the 17-oxo steroids present are reduced to secondary alcohols which are not affected by bismuthate or periodate (see below) and do not give the Zimmermann reaction. The next step consists of bismuthate or periodate oxidation, by which the dihydroxy derivatives are converted to 17-oxosteroids. These are then estimated by their reaction with m-dinitrobenzene in alcoholic alkali to give a purple compound (the Zimmermann reaction). 

Oxosteroids can be extracted from urine using suitable solvents and estimated by their reaction with m-dinitrobenzene in alcoholic alkali to give a purple colour (the Zimmermann reaction). 

In addition to the 17-ketosteroids, urinary extracts contain materials possessing significant absorption in the region of 520 mu when treated with the reagents used in the Zimmermann reaction. It is these so-called urinary chromogens which complicate the estimation of the 17-ketosteroids. 

In the Callow modification of the Zimmermann reaction an ethanolic solution of the urinary extract is treated with w-dinitrobenzene and etha-... 

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