Isosteroidal Alkaloids from Fritillaria verticillata Willd. and Their NMR Spectroscopic Characteristics  

作　　者：Nan Ma Ya-Jing Wang Gang Chen Chu-Ren Meng Chun-Lin Guo Yong-Fu Lu Si-Yang Dai Si-Xuan Liu Yong-Fu Li Chang Li Yue-Hu Pei 

机构地区：[1]Department of Medicinal Chemistry and Natural Medicine Chemistry,College of Pharmacy,Harbin Medical University,Harbin,Heilongjiang,150081 China [2]Shenyang Pharmaceutical University,Shenyang,Liaoning 110016,China

出　　处：《Chinese Journal of Chemistry》2022年第16期1945-1956,共12页中国化学（英文版）

摘　　要：Chemical investigation of Fritillaria verticillata Willd.led to the isolation of eight novel isosteroidal alkaloids(1—4,6,9—11)and four known alkaloids(5,7—8,12),including three unprecedented cis-fused D/E(13α,17α)cevanine alkaloids(1—3),one rarely cis-fused E/F(22α)cevanine alkaloid(6),and one uncommon 5β-jervine-type isosteroidal alkaloid featuring a cis-fused A/B ring moiety(11).In order to establish the structures of 1,the calculated NMR with DP4+evaluation was applied from the plausible structure candidates.The characteristic proton signals for distinguishing D/E conjunction of cevanine alkaloids were summarized.In addition,some proton and carbon signalsαto nitrogen in 6 and 7 are unobservable due to the 14N nuclear quadrupolar relaxation,based on the NMR experiments in different solvents,calculated NMR method and X-ray technology,their structures were determined.The NMR characteristics of cevanine alkaloids to distinguish orientation of long-pair on nitrogen atom withβ-hydroxyl at C-20 were also concluded.The anti-inflammatory effects of compounds 1 and 4 were evaluated in LPS-activated RAW 264.7 macrophages.Compound 4 decreased LPS-induced releases of IL-1βand IL-17αin RAW264.7 cells in a dose-dependent manner.Further mechanistic study revealed that 4 suppressed the phosphorylation of IκBαand p65 subunit to regulate the NF-κB signaling pathway.

关 键 词：ALKALOIDS Fritllaria Structure elucidation Spectroscopic characteristics INFLAMMATORY 

分 类 号：O62[理学—有机化学]