The use of extract from Wangla (coeloglossum viride (L) Hartm. Var. Bracteatum (willd.) Richter), succinate derivative esters, and a derivative and pharmaceutical acceptable salts thereof, for the manufacture of a pharmaceutical preparation for the treatment of dementia, particularly for the treatment of Alzheimer disease and Vascular dementia. Through animal experiment, it has been demonstrated that, succinate derivative esters can improve learning and memory ability in dementia rats induced by scopolamine and cyclohexenyl imine improve learning and memory ability in dementia rats induced by β -amyloid improve learning and memory ability in dementia rats induced by permanent ligation of bilateral carotid and improve memory ability of normal animals. It has the advantage of high activity, low toxicity and no inhibition to cholinesterase.
