Classification of Naturally Occurring Compounds According to Number of carbon atoms in the molecule.
# of Carbon Atoms |
Carbon Skeleton |
Possible Groupings |
5 |
C5 |
Isoprenoids |
6 |
C6 |
Simple phenols |
7 |
C6 – C1 |
Phenolic acids |
8 |
C6 – C2 |
Acetophenones; phenylacetic acid |
9 |
C6 – C3 |
Cinnamic acid derivatives; phenyl propenes; coumarins, isocoumarins, chromenes |
10 |
C6 – C4 C5 – C5 |
Naphthoquinones Monoterpenes |
13 |
C6 – C1 – C6 |
xanthones |
14 |
C6 – C2 – C6 |
Stilbenes, anthraquinones |
15 |
C6 – C3 – C6 C5 – C5 – C5 |
Flavonoids, isoflavonoids, neoflavonoids Sesquiterpenoids |
18 |
(C6 – C3) 2 |
Lignans |
20 |
(C5 – C5) 2 |
Diterpenes |
24 |
C6 – C3 – C6 – C3 – C6 |
Complex flavonoids |
30 |
(C6 – C3 – C6) 2 (C5 – C5) 3 |
Biflavonoids Triterpenoids |
40 |
(C5 – C5) 4 |
Carotenoids |
n |
(C6 – C3) n (C6 – C1) n (C6 – C3 – C6) n |
Lignins Tannins (hydrolysable) Tannins (condensed) |
Depends on N-containing heterocyclic ring |
alkaloids |
Sometimes as glycosides |