Acetogenin

File:Annonacin.svg

Chemical structure of annonacin

Acetogenins are a class of polyketide natural products found in plants of the family Annonaceae. They are characterized by linear 32- or 34-carbon chains containing oxygenated functional groups including hydroxyls, ketones, epoxides, tetrahydrofurans and tetrahydropyrans. They are often terminated with a lactone or butenolide. Over 400 members of this family of compounds have been isolated from 51 different species of plants. Many acetogenins are characterized by neurotoxicity.

Examples include:

• Annonacin
• Annonins
• Bullatacin
• Uvaricin

Structure

File:Mono-THF acetogenin core.png

Acetogenin core unit (mono-THF)

File:Acetogenin 2.png

Acetogenin terminal lactone ring core unit (unsaturated)

Structurally, acetogenins are a series of C-35/C-37 compounds usually characterized by a long aliphatic chain bearing a terminal methyl-substituted α,β-unsaturated γ-lactone ring, as well as one to three tetrahydrofuran (THF) rings. These THF rings are located along the hydrocarbon chain, along with a number of oxygenated moieties (hydroxyls, acetoxyls, ketones, epoxides) and/or double bonds.

Examples of R-groups for selected acetogenins

Compound	R1	R2	R3	R4	R5
4-deoxyannoreticuin	OH	OH	H	H	H
Annonacin	OH	OH	H	OH	H
Annopentocin A	OH	H	H	OH	H
Dispalin	OAc	OH	H	OH	H
Donnaienin C	OH	OH	H	OAc	OH
Goniotetracin	OH	OH	H	OH	H
Muricoreacin	OH	H	H	OH	H
Tonkinin A	OH	OH	O	H	H
Uvaribonone	OH	OAc	O	H	H

Research

Acetogenins have been investigated for their biological properties, but are a concern due to neurotoxicity. Purified acetogenins and crude extracts of the common North American pawpaw (Asimina triloba) or the soursop (Annona muricata) remain under laboratory studies.

Mechanism of action

Acetogenins inhibit NADH dehydrogenase, a key enzyme in energy metabolism.

External links

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