Pregnane steroids names

The classical progestins as well as the corticosteroids arc based on a steroid nucleus that incorporates a two-carbon side chain at the 17 position that often includes a carbonyl group at position 21. The hypothetical parent hydrocarbon has been assigned the name pregnane for purposes of nomenclature. While two classes of compounds, progestins and corticoids, share common biosynthetic pathways, their biological activities differ markedly. 

As shown in l- igurc 2. -1. nearly all steroids arc named as derivatives of cholestane. androstanc. pregnane, or es-trane. The standard system of numbering is illustrated with 5rt-cholestane. 

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). 

Buxus steroid alkaloids. Steroid alkaloids with 9)8,19-cyclopregnane or 9(10- 19)-afeeo-pregnane structure, but with 1 to 3 additional methyl groups at C-4 and/or C-14 as well as amino functions at C-3 and/or C-20. They are isolated from numerous species of the Buxaceae genus Buxus. To date about 200 B.s. are known. In order to achieve transparency and especially to reduce the number of incomprehensible trivial names for new compounds it was proposed to ac-... 

From this edible vegetable we were able to isolate two new saponins named as caratuberside A(24) and caratuberside B (25). Their aglycones belong to pregnane series of steroids. 

Although many conventional names (e.g., cholesterol, cortisol, testosterone, etc.) are used in steroid molecules, the use of systematic names (based on lUPAC rules) is recommended. According to the nomenclature, a complete description of a steroid molecule should include the name of their parent compound (e.g., pregnane-21C, androstane-19C, or estrane-18C series) and the name, number, position, and orientation (a or jS) of all functional groups. 

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