(-)-Huperzine A;5r-(5-alpha,9-beta,11e))-ydro-7-methyl;5,9-methanocycloocta(b)pyridin-2(1h)-one,5-amino-11-ethylidene-5,6,9,10-tetrah;HUPERIZINE;(-)-HUPERZINE A FROM HUPERZIA SERRATA;HUP, [5R-(5a,911E)]-5-Amino-11-ethylidene-5,6,9,10-tetrahydro-7-methyl-5Open