Australasian Huperzia as potential sources of Huperzine A and B

The alkaloids, Huperzine A (HupA) and Huperzine B (HupB), have been reported to be highly selective, potent and reversible inhibitors of acetylcholine esterase. Clinical trials in both China and USA have demonstrated HupA to be of therapeutic benefit for patients suffering from neurodegenerative disorders such as Alzheimer's disease. Means of synthesising isomerically pure HupA have yet to be optimised and to date all pharmaceutical production of HupA has been from the Chinese club moss Huperzia serrata which contains on average only 0.18mg g^-1 DW HupA. As a consequence, H. serrata has been listed as endangered in China. A potential solution to this problem would be to establish commercial Huperzia plantations to supply the ever growing need for HupA. Identifying species or individuals with larger biomass and/or higher HupA concentrations would be critical in establishing such large scale plantations. As little is known about the huperzine concentrations of Australasian Huperzia species, this study examined sixteen Australasian Huperzia, including three undescribed species, for their HupA and HupB contents. Concentrations of HupA and HupB were observed to vary substantially both inter- and intra-specifically, with the highest yield of HupA (1.01mg g^-1 DW) and HupB (0.34mg g^-1 DW) observed in one of the yet to be classified Huperzia samples originating from the Philippines.