Steroids studies

Adams M., Teeter J.H., Katz Y. and Johnsen P.B. (1987). Sex pheromones of the sea lamprey steroid studies on urinary products. J Chem Ecol 13, 387-395. 

Table Steroids studied by X-ray crystallography (Compounds with references 1—12 are mentioned also in the text.)...

Hydroxylation of Adrenal Steroids Studies of the biosynthesis of corticosteroids by adrenal glands, either perfused, minced, or in isolated mitochondria do not reveal any increased reaction with ascorbic acid, although the high ascorbic acid content of the adrenals has prompted many such experiments. Under certain conditions such an effect can be observed on the hydroxylation reactions which require molecular oxygen. An example of such a reaction is the... 

Ohki, E. Steroidal Studies. XV. Synthesis of 4,4-Dimethylcholecalciferol and Its Conversion into 10-Isosteroid. Chem. Pharm. Bull. 8,46 (1960). 

For a GC-MS assay using benchtop instruments, the method has excellent sensitivity. Sensitivity is lowest for testosterone with a signal-to-noise ratio (S/ N) of 2.4 for 10 pg, and highest for 5a-androstane-3a,17p diol with a S/N of 17 for 10 pg. For the steroids studied, the intra- and interassay coefficients of variation are between 2.7 and 7.6%, respectively. Accuracy was determined by spiking plasma with known amounts of steroids. The agreement between the values found and the amounts added was excellent with relative errors less than 7.5%. Standard curves were prepared by analysis of a selection of reference analyte/internal standard mixtures of known concentrations. All standard plots were linear. 

As has been noted, much of the interest in hlms of proteins, steroids, lipids, and so on, has a biological background. While studies at the air-water interface have been instructive, the natural systems approximate more closely to a water-oil interface. A fair amount of work has therefore been reported for such interfaces in spite of the greater experimental difhculties. 

Strategy Problem 6 A labelled compound for biosynthetic studies. Mevaloitic acid (TM 418) is an intermediate in the biosynthesis of terpenes and steroids (Tedder, volume 4, p.217 ff). To study exactly what happens to each carbon atom during its transformation into, say, hmonene (418A), we need separate samples of mevalonic acid labelled with in each carbon atom in the molecule. This turns our normal strategy on its head since we must now look for one carbon discoimections. You can use reagents like Na CN, and... 

Many stereoselective reactions have been most thoroughly studied with steroid examples because the rigidity of the steroid nucleus prevents conformational changes and because enormous experience with analytical procedures has been gathered with this particular class of natural products (J. Fried, 1972). The name steroids (stereos (gr.) = solid, rigid) has indeed been selected very well, if one considers stereochemical problems. We shall now briefly point to some other interesting, more steroid-specific reactions. 

The pharmaceutical industry has developed and studied a number of anabolic steroids for use in vet erinary medicine and in rehabilitation from injuries that are accompanied by deterioration of muscles The ideal agent would be one that possessed the an abolic properties of testosterone without its andro genic (masculinizing) effects Methandrostenolone (Dianabol) and stanozolol are among the many syn thetic anabolic steroids that require a prescription... 

Some scientific studies indicate that the gam in performance obtained through the use of anabolic steroids is small This may be a case though in which the anecdotal evidence of the athletes may be closer to the mark than the scientific studies The scientific studies are done under ethical conditions in which patients are treated with prescription level doses of steroids A 240 pound offensive tackle ( too small by todays standards) may take several ana bolic steroids at a time at 10-20 times their pre scribed doses in order to weigh the 280 pounds he (or his coach) feels is necessary The price athletes pay for gams in size and strength can be enormous This price includes emotional costs (friendships lost because of heightened aggressiveness) sterility testicular atro phy (the testes cease to function once the body starts to obtain a sufficient supply of testosterone like steroids from outside) and increased risk of prema ture death from liver cancer or heart disease... 

Mechanism of Action. Eew data are available that describe the effects of anaboHc steroids on protein metaboHsm even fewer data exist for assessment of direct effects of anaboHc steroids on Hpid metaboHsm in growing mminants. The lack of any consistent change in somatotropin, prolactin, insulin, or other metaboHc hormones (qv) in a total of 15 studies has been noted (1,38). 

Very Htfle data are available regarding effects of anaboHc steroid implants on the Hpid metaboHsm in growing mminants. Lipogenic enzyme activity and fatty acid synthesis in vitro were elevated in subcutaneous adipose tissue from bulls implanted with estradiol (44), which may account for the increase in fat content of carcasses reported in some studies. TBA implants have no effect on Hpogenesis in intact heifers, and only tend to reduce Hpogenic enzyme activities in ovariectomized heifers (45). 

X-Ray Crystallography. Structural data exists on more than one thousand steroids. Comparisons of the conformations obtained by x-ray crystallography have been made to the conformations obtained by other methods (161). Several studies use x-ray crystal stmctures in the study of progestins. 

Quantitative Structure—Activity Relationships. Many quantitative stmcture—activity relationship (QSAR) studies of progestins have appeared in the Hterature and an extensive review of this work is available (174). QSAR studies attempt to correlate electronic, steric, and/or hydrophobic properties to progestational activity or receptor binding affinity. A review focusing on the problems associated with QSAR of steroids has been pubUshed (175). 

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