Steroid hormones structures

A. W. Norman, R. Bouillon, M. Thomasset, eds.. Vitamin D. A Pluripotent Steroid Hormone Structural Studies, Molecular Endocrinology and Clinical Applications. Proceedings of the Ninth Workshop on Vitamin D, Orlando, Florida, May 1994, Walter de Gmyter, Berlin, 1994, p. 89. 

Figure 42-3. Cholesterol side-chain cleavage and basic steroid hormone structures. The basic sterol rings are identified by the letters A-D. The carbon atoms are numbered 1-21 starting with the A ring. Note that the estrane group has 18 carbons (Cl 8), etc.

STEROID HORMONES STRUCTURE AND CONFORMATION OF AGONISTS AND ANTAGONISTS... 

Duax WL and Griffin JF (1998) Steroid hormone structure, receptor binding and activity empirical drug design. In Codding PW (ed.) Structure-Based Drug Design, pp. 1-14. Dordrecht Kluwer Academic Publishers. 

In the early 1930 s, when the prime research aim was the commercial synthesis of the sex hormones (whose structures had just been elucidated), the principal raw material available was cholesterol extracted from the spinal cord or brain of cattle or from sheep wool grease. This sterol (as its 3-acetate 5,6-dibromide) was subjected to a rather drastic chromic acid oxidation, which produced a variety of acidic, ketonic and hydroxylated products derived mainly by attack on the alkyl side-chain. The principal ketonic material, 3j -hydroxyandrost-5-en-17-one, was obtained in yields of only about 7% another useful ketone, 3 -hydroxypregn-5-en-20-one (pregnenolone) was obtained in much lower yield. The chief acidic product was 3j -hydroxy-androst-5-ene-17j -carboxylic acid. All three of these materials were then further converted by various chemical transformations into steroid hormones and synthetic analogs ... 

We turn now to the biosynthesis of lipid structures. We begin with a discussion of the biosynthesis of fatty acids, stressing the basic pathways, additional means of elongation, mechanisms for the introduction of double bonds, and regulation of fatty acid synthesis. Sections then follow on the biosynthesis of glyc-erophospholipids, sphingolipids, eicosanoids, and cholesterol. The transport of lipids through the body in lipoprotein complexes is described, and the chapter closes with discussions of the biosynthesis of bile salts and steroid hormones. 

The great variety of structures that have by now been shown to exhibit estrogenic activity leads to the suspicion that the estrogen receptor may be unusually nonspecific compared to receptors for other steroid hormones. 

The breast cancer resistance protein (BCRP) belongs to the G-branch of the ABC-transporter family (ABCG2). In contrast to most other ABC-proteins, BCRP consists of only one transmembrane domain (TDM) with one nucleotide binding fold (NBF) at its C-terminus. Because of this structural characteristic BCRP as well as other ABC-transporters with only one TMD are termed half transporters. To achieve functional activity these transporters have to form hetero- or homodimers. BCRP is involved in the multidrug resistance of certain tumors and transports endogenous compounds like cholesterol and steroid hormones. 

Classical or conventional pharmaceutical agents in combination with lactide/glycolide polymers have been widely studied since about 1973. In general, these compounds are bioactive agents usually produced by synthetic chemistry, with molecular weights of less than a few hundred and relatively stable structures. Examples include steroid hormones, antibiotics, narcotic antagonists, anticancer agents, and anesthetics. 

Table 1 Summarized table with the more important PPCPs divided into antibiotics, steroid hormones, and other drugs. Their generic chemical structures and the use or origin are shown. Some reported data regarding their environmental occurrence and the more probable environmental fate are also given... 

Fig. 3 General structures of the most important natural and synthetic steroid hormones...

This concludes what I have to say about the steroids. A constantly recurrent theme is the sensitive nature of biological activity to chemical structure. Details of chemical structure determine if and how small molecules such as steroids interact with the large molecules, say the steroid hormone receptors, to effect biological change. Such interactions are notably sensitive to molecular size and shape. 

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