Steroid nomenclature

Implicit ia the base names are the absolute configurations at carbons 8 and 12 and the iadicated numbering systems. Derivatives of these parent stmctures are named according to terpene and steroid nomenclature rules (see Steroids Terpenoids). The lengthy and awkward nature of the chemical abstract systematic nomenclature (12) for these compounds has resulted ia the development (13) and use of simplified nomenclature based on common names. 

The position of double bonds can be designated in any of the various ways shown below. Double bonds from Cti nu go toward C9 or Cl4. and those from C20 may go toward C2I or C22. In such cases, both carbons are indicated in the name if the double bond is not between sequential ) numbered carbons (e.g.. 5steroid drugs shown in Figure 23-1. 

Steroid nomenclature is officially defined by the International Union of Pure and Apphed Chemistry (lUPAC). 

Bile acids contain hydroxyl groups, which are usually substituted at positions, C-3, C-7, or C-12 of the steroid nucleus. The three major bile acids found in man are 3a,7a,12a-trihydroxy-5P-cholan-24-oic acid 3a,7a-dihydroxy-5p-cholan-24-oic add and 3a,12a-dihydroxy-5p-cholan-24-oic acid. Because of the complexities of steroid nomenclature, bile acids are nearly always referred to by trivial names. 11108, the three major human bile acids are named cholic acid, chenodeoxycholic acid, and deoxycholic acid, respectively, and their chemical structures are shown in Fig. 1. Human bile does, however, contain small amounts of other bile acids, such as lithocholic acid (3a-hydroxy-5P-cholan-24-oic add) and ursodeoxycholic add (3a,7p-dihydroxy-5p-cholan-24-oic acid) (see Fig. 1). 

In agreement with the lUPAC Corrected Tentative Rules 7) for Steroid Nomenclature the Verairum alkaloids are classified in the jervanine (1), veratranine (2), cevanine (3), and solanidanine (4) groups. 

Note The stem name etianic acid was proposed by the Subcommittee on Steroid Nomenclature of the National Research Council as a replacement for "etiocholanic acid" in Order to avoid tbe use of the same name for parent hydrocarbons of different carbon content J. Am. Chem. Soc. 74, 2817 0952),... 

STEROID NOMENCLATURE, NUMBERING, DOUBLE BONDS AND STEREOCHEMISTRY ... 

Aliphatic side chains at position 17 are always assumed to be (3 when cholestane or pregnane nomenclature is employed. Hence, the notation 17(3 need not be used when naming these compounds. If a pregnane has a 17a chain, however, this should be indicated in the nomenclature. Finally, the final e in the name for the parent steroid hydrocarbon is always dropped when it precedes a vowel, regardless of whether a number appears between the two parts of the word (e.g., note the nomenclature for cholesterol and testosterone versus that for cortisone). For a more extensive discussion of steroid nomenclature, consult the literature (1). 

Functional Groups in Order of Priority for the Selection of the Name Suffix in Systematic Steroid Nomenclature... 

NOMENCLATUBE. The relationships in the steroids which find many counterparts in numerous solanidine derivatives suggest a rational nomenclature based on that of the steroids. The oxygen-free saturated compound V serves as the basic skeleton and is termed solanidane. This terminology will be used here, adopting the latest principles of steroid nomenclature (63). Instead of the earlier terms cis-, trans-, and alio-, the letters a, and J will be used to indicate configuration in the same way that they are used in the steroid group. 

Estrogens are female sex hormones, the most important of which are estrone, estradiol, and estriol (of the three, /3-estradiol is the most potent). Note As per convention in steroid nomenclature, the designation beta means "toward the reader," on the topside as the rings are viewed in the accompanying diagram alpha means "away from the reader," on the bottom side.)... 

The nomenclature used in this review is the same as that used in the former chapter on Solanum alkaloids (i) and follows the lUPAC-IUB recommendations for steroid nomenclature (50), with the exception of the "-anine designation of steroid alkaloids. 

Lamparczyk (1992) provided extensive coverage of the chromatographic analyses of steroids and updated information in Touchstone (1986). The book includes information on steroid nomenclature, chromatographic methods used in steroid analyses, and sample preparation. Although not restricted to TLC, the book provides extensive information on all aspects of TLC related to androgens, bile acids, ecdysteroids, estrogens, pregnanes, and corticoids. 

Ciba Foundation, Conference on Steroid Nomenclature, Hdo. Chim. Acta, 34, 1680 (1951). 

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