Steroidal compounds

The most powerful method for stmcture elucidation of steroid compounds during the classical period of steroid chemistry (- 1940 1950s) was ir-spectroscopy. As with the ultraviolet spectra, data collected on the infrared spectra of steroids are available in several books, spectmm atiases, and review articles (265,266). Unlike ultraviolet spectroscopy, even the least substituted steroid derivatives are relatively rich in characteristic absorption bands in infrared spectroscopy (264). 

A highly efficient construction of the steroidal skeleton 166 is reported by Kametani and coworkers111 in the intramolecular Diels-Alder reaction of the a, jS-unsaturated sulfone moiety of 165 (equation 117). Thus, when the sulfone 165 is heated in 1,2-dichlorobenzene for 6h, the steroidal compound 166 can be obtained in 62% yield. The compound 166 produces estrone (167) by elimination of benzenesulfinic acid and subsequent hydrogenation of the formed double bond. The stereoselectivity of the addition reflects a transition state in which the p-tosyl group occupies the exo position to minimize the steric repulsion between methyl and t-butoxy groups and the o-quinodimethane group as shown in equation 117. 

Inhibition of steroid sulphatase and sulphotransferase Steroid sulphotransferase catalyses the addition of sulphate to steroidal compounds whilst steroid sulphatase catalyses the reverse reaction. In vitro studies have demonstrated that a metabolite of genistein, 4-ethylphenol, can inhibit sulphotransferase (Harris et al, 2000). Sulphoconjugates of daidzein have also been found to potently inhibit these enzymes in vitro (Wong and... 

Human axillary odour has biological activity involving steroidal compounds 2., but it also contains 5. — the noxious (E) isomer of 3-methyl-2-hexanoic acid (E-3M2H) — whose threshold is considerably less than that of the (Z)-isomer. 

The hormone-releasing devices have a closer resemblance to standard methods of sustained release because they involve the release of a steroid compound by diffusion [198,199]. The Progestasert, a reservoir system, is shown in Fig. 16. Progesterone, the active ingredient, is dispersed in the inner reservoir, surrounded by an ethylene/vinyl acetate copolymer membrane. The release of progesterone from this system is maintained almost constant for 1 year. The effects of release are local, with none of the systematic side effects observed with orally administered contraceptives [200-207]. 

Cholesterol, mostly esterified, is utilized in the buildup of cell biomembranes. Besides, cholesterol is a precursor to biologically important steroid compounds bile acids (in liver), steroid hormones (in adrenal cortex, male and female sexual glands, and placenta), and vitamin D3, or cholecalciferol (in skin). 

The Mannich reaction can be used for the immobilization of certain drugs, steroidal compounds, dyes, or other organic molecules that do not possess the typical nucleophilic groups able to participate in traditional coupling reactions (Hermanson et al., 1992). It also can be used to conjugate hapten molecules to carrier proteins when the hapten contains no convenient nucleophile for conjugation (Chapter 19, Section 6.2). In this case, the carrier protein contains the primary amines and the hapten contains at least one sufficiently active hydrogen to participate in the condensation reaction. 

Microwave-assisted catalytic hydrogenation of steroid compounds, e. g. cholesterol, campesterol, sitosterol, etc., in the presence of Pd/C catalyst and ammonium formate in glycol solvent was fast and afforded the corresponding products in high yield (80-95%) and purity [42]. 

The answer is e. (Katzung, p 672. Hardman, pp 1477—1978.) Fludrocortisone is a synthetic steroid compound that exhibits profound mineralo-corticoid activity and some glucocorticoid activity Electrolyte and water metabolisms are affected by the administration of this compound. Fludrocortisone promotes the reabsorption of Na and the urinary excretion of K and hydrogen ions in the collecting duct of the nephron. The drug is indicated for mineralocorticoid replacement therapy in primary" adrenal insufficiency... 

Me H XA/° SnPh3 H, 13C and 119Sn ID and 2D NMR. The structure of steroidal compounds bearing a hydroxy group and a p-stannylvinyl group at the 17 position was assigned based on NMR spectra. Coordination between oxygen and tin atoms in solution was observed. 147... 

A pharmacophore model for FXR agonists based on 14 bile acid derivatives was reported by Ekins et al. The hypothesis consisted of three H features and one H BA - a common functionality pattern among steroidal compounds [42],... 

Steroids, compounds with a cyclopenta[a]phenanthrene skeleton (15), include a wide range of natural products such as sterols (e.g., cholesterol), sex hormones, adrenocorticoid hormones, cardiac glycosides and vitamin D [31]. Sterols are steroids having a hydroxyl group at position 3 of the basic skeleton. Steroids can be found both in plants and in animals. 

Corticosteroids (i.e., steroidal compounds) found in urine that possess biological properties resembling those of adrenal cortical extract, either in the increase or decrease of cholesterols levels,... 

The solvent can be an important factor in determining the outcome of hydrogenation as demonstrated by the reduction of a steroid compound (equation 66)159,160. At 100 °C... 

An iridium catalyst was used in the selective hydrogenation of a steroid compound, where the exocyclic double bond was saturated in the presence of an endocyclic one (equation 67)161. 

Many methods have been used to quantify steroidal compounds. These include RIA, gas chromatogra-phy-mass spectrometry (GC/MS), high-performance liquid chromatography (HPLC), and liquid chroma-tography-mass spectrometry (LC/MS). Although these techniques are successful in the analysis of steroids, it has been difficult to achieve quantitative analysis of small samples of neurosteroids because of their low concentrations in nervous tissues. Highly specific analytical methods are required to analyze small quantities of neurosteroids and their sulfates. Only with extremely sensitive methods of analysis is it possible to discover whether neurosteroids are synthesized in nervous tissues in quantities sufficient to affect neuronal activity, and whether these neurosteroids are distributed uniformly in brain. 

VerUcchi et al. [36] found that antibiotics, analgesics/anti-inflammatories and steroid compounds are the therapeutic classes most abundantly administered in Italian hospitals, but consistent consumption of cardiovascular compounds, tranquilizers, anti-neoplastics and anaesthetics was also detected. According to other authors in other localities [32, 41], PhCs detected in the largest amounts in hospital effluents are antibiotics, anti-epUeptics, beta-blockers, Upid regulators and... 

The apocrine glands in the axilla can secrete enormous amounts of steroids such as dihydrotestosterone and pregnenolone (Brooksbank, 1970). Three single steroid compounds have also been tested on T-shirts. Surprisingly, both sexes attributed androstenol to females. Two other synthetic compounds were attributed to one or the other sex, depending on concentration, and one was perceived as very negative. Androstenol and the two synthetic compounds have very low olfactory thresholds for humans. 

The available information on the pharmacology of STS inhibitors is restricted to a few in vitro and in vivo models. From all steroidal compounds, the irreversible inhibitor EMATE was found to be the most potent STS inhibitor with an IC50 of 65 pM [ 107]. However, it has been proposed that the sulfamate moiety of EMATE irreversibly binds to the active site and releases the steroidal backbone estrone. This means that EMATE, although a potent inhibitor of STS, counteracts its own effect by releasing estrone. The most potent derivative from a series of sulfamoyloxy-substituted stilbenes inhibited the growth of MCF-7 breast cancer cells with an IC50 value of 13 nM [111]. 

TAS-108 (SR16234) is a novel and orally active steroidal compound with a proposed additional molecular mode-of-action that is different from that of SERMs such as tamoxifen and raloxifene [157]. TAS-108 is a full estrogen receptor-a antagonist, and it should also recruit co-activator transcriptional intermediary factor 2 to ER-j6, which may have a preventive effect on bone loss [157]. 

---