289
16
at C-atom 17 (. Fig. 16.19). Stigmasterol is
an important starting material for partial
syntheses of steroid hormones.
5 Cholecalciferol (vitamin D 3 , . Fig. 16.19)
occurs in the liver oils of tuna, halibut and
cod. This steroid controls the absorption of
calcium ions in the gastrointestinal tract and
influences bone metabolism.
Another important group are the steroid hormones. These include the sex hormones and the
hormones of the adrenal cortex, the corticoids.
but especially in the gallstones from which it
takes its name (Greek cholesterol = solid bile).
Cholesterol is a central intermediate in the
biosynthesis of steroids. It is a divalent alcohol and has eight asymmetric C-atoms, which
are marked with * in . Fig. 16.19.
5 Ergosterol contains three C=C double bonds
- two of which are conjugated in ring B - and
is found mainly in yeast, but is also present in
many fungi, algae and lichens (. Fig. 16.19).
5 Stigmasterol is obtained from soybeans. It
differs from cholesterol only by the side chain
O
HO
H
C
D
Squalene epoxide
Lanosterol
A
B
. Fig. 16.17 Structure of the steroid framework of lanosterol out of squalene epoxide
. Fig. 16.18 Steroid researchers and Nobel Laureates Adolf Windaus, Adolf Butenandt and Heinrich Otto Wieland
(from left to right; © Wikipedia)
16.7 · Steroids
16
at C-atom 17 (. Fig. 16.19). Stigmasterol is
an important starting material for partial
syntheses of steroid hormones.
5 Cholecalciferol (vitamin D 3 , . Fig. 16.19)
occurs in the liver oils of tuna, halibut and
cod. This steroid controls the absorption of
calcium ions in the gastrointestinal tract and
influences bone metabolism.
Another important group are the steroid hormones. These include the sex hormones and the
hormones of the adrenal cortex, the corticoids.
but especially in the gallstones from which it
takes its name (Greek cholesterol = solid bile).
Cholesterol is a central intermediate in the
biosynthesis of steroids. It is a divalent alcohol and has eight asymmetric C-atoms, which
are marked with * in . Fig. 16.19.
5 Ergosterol contains three C=C double bonds
- two of which are conjugated in ring B - and
is found mainly in yeast, but is also present in
many fungi, algae and lichens (. Fig. 16.19).
5 Stigmasterol is obtained from soybeans. It
differs from cholesterol only by the side chain
O
HO
H
C
D
Squalene epoxide
Lanosterol
A
B
. Fig. 16.17 Structure of the steroid framework of lanosterol out of squalene epoxide
. Fig. 16.18 Steroid researchers and Nobel Laureates Adolf Windaus, Adolf Butenandt and Heinrich Otto Wieland
(from left to right; © Wikipedia)
16.7 · Steroids