Page 194 - PG 504-theoretical notes-phyto-1-2024-2025..

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Structure Determination of Terpenes and the Isoprene Rule

• The molecule is made up of the union of two or more isoprene units

• The units are usually united in a “head to tail manner”

The union of two or more isoprene units gives different classes of compounds as in the following
table:

No. of units No. of C Formula

isoprene carbon
Hemite 5 8
1 5 C H
Monote 2 10 C H
rpenes

10 16
rpenes 3 15 C H
Sesquit 15 24
erpenes 4 20 C 20 H 32
Diterpe

nes

Sisterte 5 25 C H
25 40
rpenes
Triterp 6 30 C 30 H 48

enes n 5n n
Polyter
(C 5 H 8 )
penes

175