The inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of acetylcholine, is presently the most common pharmacological approach available for Alzheimer's disease (AD). Despite research on the molecular bases of AD, potent therapeutic agent against its expansion is still needed. In searching for natural cholinesterase inhibitors, the present study was focused on the isolation of three new norditerpenoid alkaloids, uncinatine B-D together with known virescenine from Delphinium uncinatum. Chemical structures for all the isolated norditer-penoids (1-4) were established using latest spectroscopic techniques. The isolated undescribed com-pounds along with known virescenine were testified for their acetylcholinesterase inhibitory activity supported by docking analyses. Molecular docking simulation showed that the isolated compounds (1-4) were observed to adhered in the active site of AChE with docking scores -13.5322 (1),-11.8173 (2), -12.4240 (3) and -8.9352 (4) respectively. Overall results demonstrated that these natural norditerpenoids compounds were found as selective inhibitors of AChE. This is the first report regarding the use of bioactive ingredients of Delphinium uncinatum in testing against Alzhei-mer's disease.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).