Steranes

from Wikipedia, the free encyclopedia
Structural formula of sterane
Gonan's structural formula

As steranes be organic hydrocarbon - molecules referred which with the Steran the basic structure for the substance group of steroids contained. The chemical name for sterane is hexadecahydro-cyclopenta [ a ] phenanthrene . It consists of three six-membered and one five-membered ring, which are identified with the letters A, B, C and D. The molecule has six stereocenters , each on the carbon atoms that belong to two rings (5, 10, 8, 9, 13, 14). Sterane is the generic term for all stereoisomers , regardless of the configuration at the stereocenters.

As Gonane refers steranes in which the rings B and C and the rings C and D each trans are connected (that is, the groups attached to the corners of the hydrogen atoms are on opposite sides of the molecule).

AB-trans-Gonan.svg AB-cis-Gonan.svg
5 α -Gonan: Rings A and B trans linked 5 β -Gonan: Rings A and B cis linked

Rings A and B of the gonan can be linked either in cis (5 β- gonan) (that is, the hydrogen atoms are on the same side of the molecule) or in trans (5 α- gonan). This affects the stereochemistry of the molecule. In all steroid hormones that carry a C-5 hydrogen, this is α-oriented and is thus trans-linked. A β-orientation and thus a cis linkage is typical for the bile salts.

Substituents located in the half-space above the plane of the ring are referred to as the β position, those on the other side as the α position.

Derivatives

Gonan derivatives
C atoms derivative structure Surname Substance group
C 18 Estran Estrane.png 13 β -methylgonane Estrogens
C 19 Androstane Androstane.svg 10 β , 13 β -dimethylgonane Androgens
C 21 Pregnan Pregnane.svg 10 β , 13 β -dimethyl-17 β -ethyl-gonane Progestins , corticosteroids

literature

  • A. Hollerbach and DH Welte, About steranes and triterpanes in petroleum and their phylogenetic significance , in: Naturwissenschaften 64 ( 1977 ), pp. 381-382, doi: 10.1007 / BF00368741 .
  • Lorenz Schwark, Petra Empt: Sterane biomarkers as indicators of palaeozoic algal evolution and extinction events , Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 240, Issues 1–2, 6 October 2006, pp. 225–236, doi: 10.1016 / j.palaeo. 2006.03.050 .

Web links