(-) -Huperzine A (Huperzine A) is an alkaloid isolated from Huperzia serrata, with neuroprotective activity. (-) -Huperzine A is a potent, highly specific, reversible and blood-brain barrier penetrant inhibitor of acetylcholinesterase (AChE), with an IC50 of 82 nM. (-) -Huperzine A also is non-competitive antagonist of N-methyl-D-aspartate glutamate (NMDA) receptor. (-) -Huperzine A is developed for the research of neurodegenerative diseases, including Alzheimer’s disease[1][2][3][4][5].