Huperzine A
IUPAC name	(1R,9S,13E)- 1-Amino- 13-ethylidene- 11-methyl- 6-azatricyclo[7.3.1.02,7] trideca- 2(7),3,10- trien- 5-one
Other names	HupA
Identifiers
CAS number	102518-79-6
SMILES	CC3=CC1/C(C(C3)(N)C(C=CC2=O)=C(N2)C1)=C\C
Properties
Molecular formula	C15H18N2O
Molar mass	242.32 g/mol
Melting point	217-219 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Huperzine A, is a naturally occurring sesquiterpene alkaloid compound found in the plant firmoss Huperzia serrata.^[1]

Huperzine A is an Acetylcholinesterase inhibitor similar to other compounds donepezil, rivastigmine, and galantamine.

In the US Huperzine A is sold as a dietary supplement for memory support. The botanical has been used in China for centuries for the treatment of swelling, fever and blood disorders. Clinical trials in China has shown it to be effective in the treatment of Alzheimer's disease,^[2] and has been shown to enhance memory in healthy young students in one study. ^[3]

[edit] Pharmacological effects

Acetylcholinesterase inhibition^[4] and NMDA receptor antagonism.^[5]

Huperzine A has also attracted the attention of US medical science. It is currently being investigated as a possible treatment for diseases characterized by neurodegeneration – particularly Alzheimer’s disease.^[6][7] It has been found to be an inhibitor of the enzyme acetylcholinesterase.^[8] The structure of the complex of huperzine A with acetylcholinesterase has been solved by X-ray crystallography (PDB code: 1VOT; see the 3D structure).This is the same mechanism of action of pharmaceutical drugs such as galantamine and donepezil used to treat Alzheimer's disease. Huperzine A is also a NMDA receptor antagonist^{[citation needed]} which protects the brain against glutamate induced damage, and it increases nerve growth factor levels.^{[citation needed]}

Clinical trials in China have shown that huperzine A is comparably effective to the drugs currently on the market, and may even be a bit safer in terms of side effects.^{[citation needed]} Currently, the National Institute on Aging is conducting a Phase II clinical trial to evaluate the safety and efficiency of huperzine A in the treatment of Alzheimer's disease in a randomized controlled trial of its effect on cognitive function. Recently, it has been investigated for its effectiveness against epilepsy in an initial 20-person clinical study by Harvard University neuroscientists examining its worth and side effects in those who are not satisfactorily treated by existing pharmaceuticals.^{[citation needed]}

Possible side effects may include breathing problems, tightness in the throat or chest, chest pain, skin hives, rash, itchy or swollen skin, upset stomach, diarrhea, vomiting, hyperactivity and insomnia.^[9] Most adverse events were cholinergic in nature and no serious adverse events occurred. Huperzine A is a well-tolerated drug.^[10]

[edit] See also

• Acetylcholinesterase inhibitor and AChE inhibitors and substrates in Proteopedia

[edit] References