LiCl-promoted amination of β-methoxy amides (γ-lactones)
作者:Ru Zhao、Bing-Lin Zeng、Wen-Qiang Jia、Hong-Yi Zhao、Long-Ying Shen、Xiao-Jian Wang、Xian-Dao Pan
DOI:10.1039/d0ra07170f
日期:——
An efficient and mild method has been developed for the amination of β-methoxy amides (γ-lactones) including natural products michelolide, costunolide and parthenolide derivatives by using lithium chloride in good yields. This reaction is applicable to a wide range of substrates with good functional group tolerance. Mechanism studies show that the reactions undergo a LiCl promoted MeOH elimination
The dried roots of Saussurea lappa, called costus roots, are used in the traditional system of medicine for the treatment of cancer. In our investigation for the anticancer constituents from the hexane extract of this plant, a new sesquiterpene (1) was isolated along with the known compounds costunolide ( 2), beta-cyclocostunolide (3), dihydro costunolide (4) and dehydro costuslactone (5). Their structures were established by the extensive spectroscopic analyses. In addition, costunolide and beta-cyclocostunolide derivatives were synthesized using Michael-type addition reaction of NaOMe to the alpha-methylene-gamma-lactone moiety. All the compounds were tested for their in vitro cytotoxic activity. Compound 1 exhibited potent cytotoxic activity and other compounds displayed moderate activity. (c) 2008 Elsevier Ltd. All rights reserved.
Inhibition of TNF-α-Induced Inflammation by Sesquiterpene Lactones from Saussurea lappa and Semi-Synthetic Analogues
We investigated the tumor necrosis factor-alpha (TNF-α) inhibitory activity of sesquiterpenes fromSaussurealappa root extracts. According to the hexane and EtOAc extracts showing significant activity with IC50 values of 0.5 and 1.0 µg/mL, respectively, chromatographic fractionation of the extracts was performed and led to the isolation of 10 sesquiterpenes (1: -10: ). Costunolide (1: ), a major compound