Steroids molecular structure

Steroid chemistry before 1950 is a story of remarkable achievements with primitive tools. The unravelling of steroid molecular structures, their interconversion, and their synthesis during this period, demand the highest admiration for the early generations of steroid chemists, whose approach had to be largely empirical. Today s techniques of spectroscopy and chromatography were unknown or in their infancy, and the conformational aspects of steroids had not been realised. Very many steroid reactions were documented, but few were really understood. The study of reaction mechanisms lay in a specialised field which hardly impinged upon the chemistry of natural products . 

Steroid Molecular Structure, Protein Interaction and Biological Function... 

See also Steroids, Molecular Structures and Properties of Lipids (from Chapter 10), Bile Acids, Steroid Hormone Synthesis... 

Duax, W. L., Griffin, J. F., Ghosh, D. (1994). Steroid molecular structure, protein interaction and biological function. Structure Correlation, Vol. 2 (Biirgi H.-B., Dunitz J. 

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. 

Cardiolipin or diphosphatidyl glycerol is one of the most ancient membrane phospholipids from phylogenic aspects. It is surprising for such a complex molecule as cardiolipin to have evolved as one of the major membrane lipids in prokaryotics, when steroids such as cholesterol and phytosterols did not. In eukaryotic cells, cardiolipin is exclusively localized within the mitochondria where it is particularly emiched in the outer leaflet of the inner membrane. Even though a molecular structure of cardiolipin has been conserved in entire organisms, its biological significance has escaped attention except in the case of anti-cardiolipin auto-antibodies which are clinically associated with the Wasserman reaction. 

Although steroids have been studied for many years, steroid hormones continue to be a rich area of medicinal chemistry study. Steroids continue to be evaluated for their therapeutic role in the treatment of cancer, especially malignancies whose growth characteristics are hormonally responsive. In recent years, the increased recognition of the role of steroids in the brain has resulted in ongoing projects to evaluate steroids as general anasthetics and anticonvulsants. Also, the search for compounds that bind to steroid receptors, but which are not steroidal in their molecular structure, is another important area of research. 

Women produce testosterone without testicles. (DUH ) A woman s sex hormones are produced starting at the adrenal glands and ovaries. Through a series of conversion enzyme pathways (chemicals that alter the molecular structure of other chemicals) their bodies synthesize the necessary sex, Glucocorticoid, and Mineralocorticoid steroids. 

Many Anabolic/Androgenic Steroids (AAS) are available in an oral form. Unfortunately some are also quite toxic to the liver. Orally administered AAS are very susceptible to first pass liver deactivation unless chemical molecular structures are altered to make them harder to deactivate. When an oral AAS is swallowed it enters the stomach where it is partially broken down and passed to the small intestines. The small intestines contain a group of enzymes called CYP-450 s. These enzymes begin to break down the AAS further in an attempt to deactivate it. The AAS is then absorbed through intestinal mucosa cells and transferred to the liver portal vein for further deactivation into inactive chemicals such as etiocholanone. These chemicals are then conjugated with glucuronic acid and excreted in urine. Up to 100% of the original compound can be deactivated in this process which is known as first pass deactivation. 

Lecithin (phosphatidylcholine) is a phospholipid, which may be isolated from either egg yolk or soybeans. It is commercially available in high purity for medical uses and has been used to enhance the absorption of insulin in vivo [26]. The antibiotic sodium fusidate, a steroid similar in molecular structure to bile salts has also been shown to have permeation enhancing properties for insulin in vitro [41]. 

We have researched the inclusion abilities of bile acid derivatives by using more than one hundred organic compounds as guest candidates. The inclusion phenomena vary from one case to another, indicating that subtle changes in molecular structures induce alteration in their molecular assemblies. In fact, X-ray diffraction studies prove that the steroidal hosts form various assemblies such as monolayers, bilayers, helical tubes, and so on, as shown in Figure 2. Therefore, systematic investigation of inclusion crystals of bile acid derivatives is expected to reveal a relationship between their molecular structures, assemblies and inclusion behavior. 

T. Yokota K. Mori, Molecular Structure and Biological Activity of Brassinolide and Related Brassinosteroids. In Molecular Structure and Biological Activity of Steroids M. Bohl, W. L. Duax, Eds. CRC Press Boca Raton, FL, 1992 pp 317-340. 

X-Ray crystallographic studies of steroids continue to reveal conformational subtleties, as well as helping in some instances with the determination of molecular structures. 

Simon and his coworkers have developed (426) a quantitative 3D-QSAR approach, the minimal steric (topologic) difference (MTD) approach. Oprea et al. (452) compared MTD and CoMFA on affinity of steroids for their binding proteins and found similar results. Snyder and colleagues (453) developed an automated method for pharmacophore extraction that can provide a clear-cut distinction between agonist and antagonist pharmacophores. Klopman (404,454) developed a procedure for the automatic detection of common molecular structural features present in a training set of compounds. This has been used to produce candidate pharmacophores for a set of antiulcer compounds (404). Extensions (454)of this approach allow differentiation between substructures responsible for activity and those that modulate the activity. 

Inorganic Reaction Mechanisms Molecular Spectroscopy Molecular Structure by Diffraction Methods Radlochamistry Rsaction Kmetfcs Saturated Haterocyclic Chemistry Statistical Mechanics Surface and Defect Properties of Solida Terpenoids and Steroids... 

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