Page 239 - PG 504-theoretical notes-phyto-1-2024-2025..

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

2) Ginkgolide A, B, C, J and M
▪ They are diterpene lactones isolated from ginkgo leaves, Ginkgo biloba, family Ginkgoaceae

(Gymnosperm).
▪ Five ginkgolides are isolated; ginkgolide A, B, C and J from leaves, ginkgolide M is isolated from

roots.
▪ Structure characters:

1) 20 carbon atoms, in the form of cage structure.
2) Tertiary butyl group.

3) 6 five-membered rings:

a) A spiro-nonane rings
b) A tetrahydrofuran moiety
c) 3 lactone ring (of tetrahydrofuran)

H
O O
H 3 C
HO O
O
C
O
O OH
O C CH 3
H CH 3
H CH 3
H
H
Ginkgolide A

▪ Pharmacological action: Platelet Activator Factor Antagonist (PAF-Antagonist)

▪ Uses:
Leaves extract is used for improving peripheral and cerebral circulation in the elderly with

symptoms of: - Loss of short term memory.

- Loss of hearing.

- Loss of concentration.

▪ There is a seasonal variation of the terpenes and flavonoids in the ginkgo leaves:

▪ Terpenes: Maximum concentration in the early autumn.
▪ Flavonol glycosides: Maximum concentration in spring.

▪ Biflavones: Maximum concentration in the early autumn.

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