A new C19-diterpenoid alkaloid named gyalanutine A (1) and fourteen known compounds 2-15 were isolated from the plant of Delphinium gyalanum C. Marquand & Airy Shaw. Compound 1 displayed an unusual lycoctonine-type C19-diterpenoid alkaloid skeleton with the cleavage of N-C19 and C7-C17 bonds, and the construction of the N-C7 bond. Structures were identified by multiple spectroscopic analyses including 1 D, 2 D NMR, IR and HR-ESI-MS. Compounds were tested for acetylcholinesterase inhibitory and anti-inflammatory activity. © 2021 Informa UK Limited, trading as Taylor & Francis Group.