Thin-layer chromatography of corticosteroids

Some aspects of the use of thin-layer chromatography in a limit test for related foreign steroids

To attain the maximum separation of the steroid impurities in pharmaceutically important synthetic corticosteroids the running of two or more chromatograms using different solvent systems is recommended. Using adsorption chromatography, solvent systems of the type 1,2-dichloroethane: methanol:water, 95:5:0·2, give the most satisfactory general separations. Some steroids can best be separated by partition chromatography, using formamide as the stationary phase and chloroform:ether:water, 80:20:0·5, or cyclohexane:tetrachloroethane:water, 50:50:0·1, as the mobile phase. A spray reagent of 0·05% tetrazolium blue and 8% sodium hydroxide in methanol is recommended. The amounts of foreign related steroids can be limited by running standard amounts of impurities alongside the steroid under test and comparing the colour intensities of the impurities in the steroid with those of the standards.

Quantitative TLC determination of epimeric ratios of 16-methyl 17-ketone oxidation products of dexamethasone and related drugs

A TLC system sensitive enough to detect, identify, and allow quantitation of the 16-methyl alpha- and beta-epimers of 9-fluoro-11 beta-hydroxy-16-methylandrosta-1,4-diene-3,17-dione is described. These epimeric 17-ketones may be present as impurities in dexamethasone, betamethasone, or related drugs. A spectrodensitometer with a TLC scanning attachment was used, and results from densitometry compared favorably with quantitation by high-performance liquid chromatography, as was described recently. TLC was convenient in the rapid examination of drug samples for the detection and identification of epimeric 17-ketones and for the determination of the alpha to beta ratio of such epimers. Various applied photographic techniques for documenting TLC data are described.

Isolation of urinary C-20 alpha- and C-20 beta-hydroxy-C21-steroid metabolites in cases of congenital adrenal hyperplasia, postpubertal virilizing syndrome and polycystic ovary syndrome

The proportion of 20 alpha/20 beta-epimers of the urinary C21-steroid metabolites was estimated in normal volunteers and in patients with congenital adrenal hyperplasia (CAH), postpubertal virilizing syndrome (PVS) and polycystic ovary syndrome (POS). In the normal individuals 20 alpha- and 20 beta-epimers of 5 beta-pregnane-3 alpha, 17 alpha, 20-triol (pregnanetriol) and 5-pregnene-3 beta, 17 alpha, 20-triol (5-pregnenetriol) were measured. In the other case 20 alpha- and 20 beta-epimers of the characteristic, representative metabolites were also investigated. In 26 of 27 normal persons and in all the patients with normotensive CAH, PVS and POS the 20 beta-epimer comprised 0-10% of the total pregnanetriol. The 20 beta-epimer of 5-pregnenetriol was found in only one normal case (6% of the total). The percentage of 20 beta-epimers of 3 alpha, 17 alpha, 20-trihydroxy-5 beta-pregnan-11-one, 5 beta-pregnane-3 alpha, 11 beta, 17 alpha, 20-tetrol (in the normotensive CAH, PVS and POS) and 5 alpha- or 5 beta-pregnane-3 alpha, 17 alpha, 20, 21-tetrol (in the hypertensive CAH) varied from nil to 76%. The effect of functional groups and the stereochemistry of the molecule on the direction of C-20-keto group reduction is discussed; the existence of additional factors determining this reduction in certain pathological conditions is suggested.

Lipids in plant tissue cultures. IV. The characteristic patterns of lipid classes in callus cultures and suspension cultures

Lipids from callus cultures and suspension cultures of higher plants constitute 5 to 8% of the dry tissue's weight. The predominant lipid classes are the sterols, steryl esters, steryl glycosides and esterified steryl glycosides. Considerable amounts of a variety of sterylglycolipids, whose structures are not completely elucidated, are also present. Triglycerides and phospholipids occur in small proportions, whereas monogalactosyl diglycerides, digalactosyl diglycerides and sulfoquinovosyl diglycerides are present only in traces, if at all. Beta-Sitosterol is the predominant constituent sterol, stigmasterol and campesterol as well as a variety of as yet unidentified sterols occur in smaller proportions. The major constituent fatty acids are palmitic, oleic, linoleic and linolenic acids. Saturated very long-chain fatty acids are found in smaller proportions. Unusual fatty acids, such as epoxy acids, which occur in the seed lipids of certain plants, are not found in tissue cultures derived from these plants. Clucose and traces of galactose are the only sugars obtained by acid hydrolysis of the glycolipids occurring in plant tissue cultures.