592
W. SANDERMANN
Carbohydrates, Fats
I
CH 3 CO- CoA
(I)
I
CH 3 CO-CH 2 -CO-CoA
(Π)
HO
Leucine
COOH
*- Isovaleryl-CoA
t
ATP CO,
Y
/
>
CH
ADP+ P I
CO· CoA
(in)
CH 2
—
CO· CoA
(V)
CH
COOH
TpNH ^ HO
HO"
N
COOH
CH,
^2TPN
CH 2 OH
MVA
(VI)
Isomerase
CH 2 · PP
y, γ -Dimethylallyl
pyrophosphate
(X)
CH 2 -PP
Isopentenyl
pyrophosphate
("Active isoprene")
(IX)
Geranyl-PP—φ(XI).
Terpenes
Farnesyl-PP
(ΧΠ)
TPNHN
I\!
X TPN
Sterols,
steroids
Cyclic
triterpenes
»- Squalene
Geranylgeranyl-PP
(ΧΙΠ)
TPNHN
->- Sesquiterpenes
-»- Carotenoids
^TPN
->~ Diterpenes
CH 3
H[CH 2 —CH=C-CH 2 ] n Η· ΡΡ
I
Ubiquinones
Vitamins K 2 (n = 6-10)
Caoutchouc (n> 100,000)
FIG. 1. Biogenesis of terpenes and terpenoids. Abbreviations: ATP, adenosine
triphosphate; ADP, adenosine diphosphate; TPN and TPNH, respectively, oxidized
and reduced triphosphopyridine nucleotide; CoA, coenzyme A; MVA, mevalonic
acid; PP, pyrophosphate.
ß-hydroxy-ß-methylglutaryl coenzyme A (V), is derived on the one
hand from fats and carbohydrates through acetyl coenzyme A (I) and
on the other hand from leucine through the coenzyme A compounds of
isovaleric acid, /?-methylcrotonic acid (=/?,/!^dimethylacrylic acid) (III),
and /?-methylglutaconic acid (IV). This precursor, on reduction, yields