Please use this identifier to cite or link to this item:
Popov, Sergey A.
Golubeva, Tatiana S.
Waldvogel, Siegfried R.
Shults, Elvira E.
|Title:||Electrosynthesis of stable betulin-derived nitrile oxides and their application in synthesis of cytostatic lupane-type triterpenoid-isoxazole conjugates|
|Online publication date:||15-Nov-2022|
|Year of first publication:||2021|
|Abstract:||Novel lupane-type triterpenoid-isoxazole conjugates were designed by direct placing of isoxazole linker at C(17) of triterpenoid. The suggested synthetic sequence demonstrates successful combination of electro-organic synthesis and conventional approaches. TEMPO-mediated electrooxidation of betulin to betulinal was developed and optimized at boron-doped diamond anodes with potassium acetate as inexpensive supporting electrolyte. Betulinal-derived oxime was further selectively electro-oxidized at a graphite anode to nitrile oxide, which proved to be stable and isolable species. The same reaction sequence was performed with 3β-lupane-3,28-diol. Nitrile oxides were characterized by 15N NMR and X-ray crystallography. The isolable nitrile oxides allowed creation of isoxazole library by 1,3-dipolar cycloaddition reactions with various alkynes. Some of the title conjugates exhibit cytostatic properties against breast cancer cell line MCF7, glioblastoma multiform cell line U-87 MG and lung carcinoma cell line A549 with growth inhibition (GI50) concentrations up to 11 μm, while being harmless to immortalized human fibroblasts hTERT (GI50 >100 μm).|
540 Chemistry and allied sciences
|Institution:||Johannes Gutenberg-Universität Mainz|
|Department:||FB 09 Chemie, Pharmazie u. Geowissensch.|
|Information on rights of use:||https://creativecommons.org/licenses/by/4.0/|
|Journal:||European journal of organic chemistry|
|Pages or article number:||2557|
|Appears in collections:||JGU-Publikationen|
Files in This Item:
|electrosynthesis_of_stable_be-20221115115020172.pdf||881.02 kB||Adobe PDF||View/Open|