Organic steroids

Steroid receptors are highly specific macromolecules found in central regulatory organs (e.g., pituitary, hypothalamus), in various end-point target tissues (e.g., uterus, vagina, prostate), and in lower concentrations in the brain, liver, kidney, ovary, and many other organs. Steroid hormones exhibit remarkable tissue selectivity when binding to these... 

Steroids are an important class of lipids. They occur in animals mostly as hormones, the chemical substances made by the body that control the activity of certain cells or organs. Steroid molecules all have a basic four-ring structure one ring with five carbons and three rings with six carbons. 

Mammalian nuclear receptors for steroid hormones (SHRs) are of great importance in physiology and medicine, because they control not only developmental pathways but also regulate central physiological and metabolic functions in the adult organism. Steroid hormones and vitamin D are derivatives of cholesterol. Structures of vitamin D3 and of... 

Ivanchina NV, Kicha AA, Stonik VA (2011) Steroid glycosides from marine organisms. Steroids 76 425 54... 

Most steroids function as chemical messengers, or hormones, that are secreted by endocrine glands and transported through the bloodstream to their target organs. Steroids and their derivatives are also among the most widely used therapeutic agents. They are used in birth control and hormone replacement therapy and in the treatment of inflammatory conditions and cancer. 

Open-chain 1,5-polyenes (e.g. squalene) and some oxygenated derivatives are the biochemical precursors of cyclic terpenoids (e.g. steroids, carotenoids). The enzymic cyclization of squalene 2,3-oxide, which has one chiral carbon atom, to produce lanosterol introduces seven chiral centres in one totally stereoselective reaction. As a result, organic chemists have tried to ascertain, whether squalene or related olefinic systems could be induced to undergo similar stereoselective cyclizations in the absence of enzymes (W.S. Johnson, 1968, 1976). 

A major trend in organic synthesis, however, is the move towards complex systems. It may happen that one needs to combine a steroid and a sugar molecule, a porphyrin and a carotenoid, a penicillin and a peptide. Also the specialists in a field have developed reactions and concepts that may, with or without modifications, be applied in other fields. If one needs to protect an amino group in a steroid, it is advisable not only to search the steroid literature but also to look into publications on peptide synthesis. In the synthesis of corrin chromophores with chiral centres, special knowledge of steroid, porphyrin, and alkaloid chemistry has been very helpful (R.B. Woodward, 1967 A. Eschenmoser, 1970). 

Fried, J. Edwards, J, A, 1972, Organic Reactions in Steroid Chemistry, Vols, 1 2, Van Nostrand New York... 

The path from squalene (114) to the corresponding oxide and thence to lanosterol [79-63-0] (126), C qH qO, cholesterol [57-88-5] (127), and cycloartenol [469-38-5] (128) (Fig. 6) has been demonstrated in nonphotosynthetic organisms. It has not yet been demonstrated that there is an obligatory path paralleling the one known for generation of plant sterols despite the obvious stmctural relationships of, for example, cycloartenol (128), C qH qO, to cyclobuxine-D (129), C25H42N2O. The latter, obtained from the leaves of Buxus sempervirens E., has apparentiy found use medicinally for many disorders, from skin and venereal diseases to treatment of malaria and tuberculosis. In addition to cyclobuxine-D [2241-90-9] (129) from the Buxaceae, steroidal alkaloids are also found in the Solanaceae, Apocynaceae, and LiUaceae. 

Although a tremendous number of fermentation processes have been researched and developed to various extents, only a couple of hundred ate used commercially. Fermentation industries have continued to expand in terms of the number of new products on the market, the total volume (capacity), and the total sales value of the products. The early 1990s U.S. market for fermentation products was estimated to be in the 9-10 x 10 range. The total world market is probably three times that figure, and antibiotics continue to comprise a primary share of the industry. Other principal product categories are enzymes, several organic acids, baker s yeast, ethanol (qv), vitamins (qv), and steroid hormones (qv). 

Experimental procedures have been described in which the desired reactions have been carried out either by whole microbial cells or by enzymes (1—3). These involve carbohydrates (qv) (4,5) steroids (qv), sterols, and bile acids (6—11) nonsteroid cycHc compounds (12) ahcycHc and alkane hydroxylations (13—16) alkaloids (7,17,18) various pharmaceuticals (qv) (19—21), including antibiotics (19—24) and miscellaneous natural products (25—27). Reviews of the microbial oxidation of aUphatic and aromatic hydrocarbons (qv) (28), monoterpenes (29,30), pesticides (qv) (31,32), lignin (qv) (33,34), flavors and fragrances (35), and other organic molecules (8,12,36,37) have been pubflshed (see Enzyp applications, industrial Enzyt s in organic synthesis Elavors AND spices). 

The pharmaceutical industry employs ozone in organic reactions to produce peroxides as germicides in skin lotions, for the oxidation of intermediates for bacteriostats, and in the synthesis of steroids (qv) such as cortisone (see Disinfectants and antiseptics). Vitamin E can be prepared by ozonation of trimethyUiydroquinone. 

This explosion in steroid chemistry both stimulated and was aided by the development of conformational analysis (10). Many basic, physical organic chemistry principles were estabUshed as a result of the study of the logically predictable chemistry of the rigid perhydro-l,2-cyclopentenophenanthrene, steroid skeleton. 

Steroids are nearly ubiquitous to all living organisms and have a variety of structural variations. Herein a brief overview of a few natural steroids from both plant and animal sources that have interesting biological activities or industrial importance is given. 

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