Ginkgolide

thumb|Chemical structure of gingkolide B

Ginkgolides are biologically active terpenic lactones present in Ginkgo biloba. They are diterpenoids with 20-carbon skeletons, which are biosynthesized from geranylgeranyl pyrophosphate.

Examples

thumb|left|Chemical structure of ginkgolides

{| class="wikitable"

|+Ginkgolides

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||Name||R¹||R²||R³

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|Ginkgolide A||OH||H||H

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|Ginkgolide B||OH||OH||H

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|Ginkgolide C||OH||OH||OH

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|Ginkgolide J||OH||H||OH

|-

|Ginkgolide M||H||OH||OH

|}

Ginkgolide A

Ginkgolide A has a chemical formula of C₂₀H₂₄O₉, its CAS No. is 15291-75-5.

Aside from the G. Biloba tree, this ginkgolide has also been reported to be present in Machilus wangchiana. It is also biologically active.

A study has concluded that Ginkgolide A can induce the CYP1A2 enzyme, but not as much as other chemicals present in Ginkgo. This means that Ginkgolide A can increase the action of CYP1A2. Ginkgolide A also acts as an antagonist of glycine receptors and α₁β₂γ_2L GABA_A receptors. Additionally, it acts as a powerful PAF antagonist.

Ginkgolide B

Ginkgolide B, specifically, is a diterpenoid trilactone with six five-membered rings. It contains a spiro[4,4]-nonane carbocyclic ring, a tetrahydrofuran ring, and a very specific tert-butyl group at one of the rings (Figure 1).

The class of ginkgolides was first isolated from the tree Ginkgo biloba in 1932.

Ginkgolide C

Ginkgolide C is a ginkgolide with the chemical formula of C₂₀H₂₄O₁₁ and the CAS number 15291-76-6. It is an inhibitor of PAFR with an IC50 value of 7.5μM. This ginkgolide also appears to possess anti-inflammatory properties and activity against oxidative stress. A total synthesis of Ginkgolide C has also been reported.

Background

It is extracted from the root bark and leaves of the Ginkgo biloba (' meaning "silver apricot") tree found native in China. It is marketed to other countries that include Korea, France, the United States, etc. for the drug and clinical properties of the extracts. Present in the tree is less than 0.1 to 0.25% of ginkgolide B, the most abundant being ginkgolide A.

Potential applications

This class of molecules has been studied for its potential to act as a platelet-activating factor receptor antagonist.

Ginkgolide B has been investigated for its potential to reducing migraine frequency.

Ginkgolide B is also used in treatment for cerebrovascular disease. Research has also proven that ginkgolide B can also treat migraines in young ages.