Isolated compounds from Adelostemma gracillimum refined fractions and compositions containing the compounds are provided by the present invention. Adelostemma gracillimum refined fractions and the extraction process thereof are also provided by the present invention. The uses of the compounds and the Adelostemma gracillimum refined fractions for inhibiting the activities of NMDA receptor or amyloid-beta peptide, for improving memory, and for treating neurodegenerative diseases, neuropathological conditions or epilepsy are further provided by the present invention.
