Steroid hormones androstanes

The 13C chemical shifts of selected androstanes, pregnanes and estranes are given in Table 5.10. The formulae of the parent compounds and some related steroid hormones with numbering of the carbon atoms are given below ... 

Fig. 10.15. Gradient elution CEC separation of steroid hormones. Conditions capillary, 9.6 (17.6) cm x 50 pm i.d. packed with 6 pm Zorbax ODS mobile phase, A, acetonitrile-10 raM borate, pH 8 (65 35 v/v) B, acetonitrile-10 mM borate, pH 8 (85 15 v/v), 0-100% B in 5 min, 100% B for 3 min at 0.1 ml/min 14 kV 25°C detection, UV at 205 nm injection, 1 kV/0.5 s. Peak identification 1, formamide 2, corticosterone 3, testosterone 4, androsten-3,17-dione 5, androstan-3,17-dione 6, pregnan-3,20-dione. Reproduced with permission from Huber et al. [68]. Copyright 1997 American Chemical Society.

New derivatives of steroidal hormones, prepared for biological evaluation, include 17-dialkylaminoalkanoates and other novel esters of 17a-hy-droxyprogesterone," trimethylsilyl ethers of 17a-hydroxyprogesterone, testosterone, 19-nortestosterone, 17a-methyltestosterone, and other androstane... 

Steroidal amines with nitrogen at C-3 or C-20 can be converted into steroidal hormones." Beckmann rearrangement of the oxime (45) of funtumine gives 3a,17j3-diamino-5a-androstane (46). Ruschig deamination of the latter gives androstanedione In the same way, the alkaloids of H. floribunda,... 

Several groups are included in this class of steroids including corticosteroids, pregnanes, androstanes and oestranes. Extensive reviews on the chromatography of these compounds have been previously published (Heftman, 1983 Heftman and Lin, 1982 Purdy et al, 1982 O Hare and Nice, 1982 Schmidt, 1982). It is not the purpose of this section to provide a comprehensive review of the Uterature but to provide the potential chromatographer with a number of alternative strategies for the separation and detection of the various steroid hormones. For ease of reference the individual classes of steroid hormones have been separated into individual sub-sections. 

If a substituent is oriented trans to the 10-methyl group and points down in the flat model, then such a substituent is said to be in a-position, symbolized in formulas by a dotted line as valence bond. Androstane, with imns-fused rings, has its hydrogen on C atom 5 in hydroxyl groups. Cholesterol is a 3/3-hydroxy compound. These designations will be very important in the field of steroid hormones, where isomers are frequently found together. 

Steroids that possess angular methyl groups at both the 10 and 13 positions but which are devoid of acetyl side chains at the 17 position are usually classed as derivatives of the hypothetical hydrocarbon, androstane. The endogenous male sex hormones, such as, for example, testosterone, can all be classified as androstanes as will be noted below, the biological activity of compounds in this stmctural class goes beyond that narrow definition. 

Increased P450 synthesis requires enhanced transcription and translation. A cytoplasmic receptor (termed AhR) for polycyclic aromatic hydrocarbons (eg, benzo[a]pyrene, dioxin) has been identified, and the translocation of the inducer-receptor complex into the nucleus and subsequent activation of regulatory elements of genes have been documented. A pregnane X receptor (PXR), a member of the steroid-retinoid-thyroid hormone receptor family, has recently been shown to mediate CYP3 A induction by various chemicals (dexamethasone, rifampin) in the liver and intestinal mucosa. A similar receptor, the constitutive androstane receptor (CAR) has been identified for the phenobarbital class of inducers (Sueyoshi, 2001 Willson, 2002). 

Most steroids have an oxygen functional group (=0 or —OH) at C3 and some kind of side chain or other functional group at Cl7. Many also have a double bond from C5 to either C4 or C6. The structures of androsterone and cholesterol serve as examples. Androsterone, a male sex hormone, is based on the simple androstane ring system. Cholesterol is a common biological intermediate and is believed to be the biosynthetic precursor to other steroids. It has a side chain at C17 and a double bond between C5 and C6. 

Aldosterone, essentially a corticosteroid in which the methyl group at Cjg is oxidized to a carboxaldehyde, was the last endogenous steroid to be isolated in a form suitable for structural studies. This hormone controls via its action on the kidney both body electrolyte balance and blood volume. A number of modified androstanes, all of which feamre a spirobutyrolactone at C17, act as aldosterone antagonists Those 17-spirobutyrolactones consequently show diuretic and... 

Cjg-C2i steroids, e.g., androstane derivatives, may act as hormones. Steroids with longer alkyl chains on C17 are inactive as messengers of biological information. Relatively large amounts of Cjg-C steroids are ubiquitous in cell membranes. Typical foodstuffs and human tissues containing massive amounts of cholesterol (animals) or ph)d osterols (plants) are given in Table 3.2.1. 

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