Studies On Diterpene Alkaloids From Aconitum Fischeri Var.arcuatum And Their Biological Activities

Aconitum fischeri var.arcuatum（Rannculaceae）is mainly distributed in northeast China.In previous studies,diterpenoid alkaloids,the main characteristic components of this genus,have displayed various bioactivities,such as anticancer,analgesic and anti-inflammatory activities.To discover the new and potentially bioactive diterpenoid alkaloids,investigation on the alkaloid composition of Aconitum fischeri var.arcuatum has been carried out.In this thesis,chemical investigation of Aconitum fischeri var.arcuatum led to the isolation of twenty-seven compounds.Their structures were elucidated based on various spectroscopic methods.Compounds 1 and 2 were all isolated as natural products for the first time.Compound 1 was determined as a new one,named as arcutisine,which was a rare denudatine-type C₂₀-diterpenoid alkaloid bearing a C-15 carbonyl ketone and 16,17-epoxy group.Compound 2 was a known C₁₉-diterpenoid alkaloid with a nitrone functionality.Other twenty-five known compounds were identified as nagadine,piepunensine A,lijiestrandine,hemsleyaconitine G,talatisamine,14-acetyltalatisamine,aconitine,14-acetyl-8-O-methyltalatisamine,acoforine,14-benzoylaconine,indaconitine,3-deoxyaconitine,columbidine,hemsleyanine C,cammaconine,mesaconitine,14-benzoylmesaconitine,hypaconitine,N-deethyltalatisamine,sachaconitine,aconosine,akiran,dolaconine,vilmorine D and anthoroisine G.Compounds 1-6,8-22 and 24-27 were isolated from Aconitum fischeri var.arcuatum for the first time.Compounds 1-2,4,6-7,9-12,14-16 and 18-27 were tested for their cytotoxic activities on RAW264.7 macrophages,and all of them showed no toxic at the concentration of 40μM.Then these twenty-two compounds were further evaluated for their inhibitory activities against LPS-induced nitric oxide production in RAW264.7 cells.Among them,compounds 7,11,23 and 25 showed weak effect with the inhibition rate of 33.49%,33.78%,32.56%and32.00%.Compounds 1-27 were investigated for their acetylcholinesterase inhibitory effects.However,none of them exhibited obvious inhibitory activity on acetylcholinesterase.