- Semisynthesis of natural flavones inhibiting tubulin polymerization, from hesperidin
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Semisynthesis of 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone (1), a natural flavone that binds with high affinity to tubulin, was performed from hesperidin, the very abundant Citrus flavanone, by a five-step sequence. The last step of the synthesis also gave rise to 5,3'-dihydroxy-3,6,7,4'- tetramethoxyflavone (= casticin or vitexicarpin) (10), 5,3'-dihydroxy-3,7,8,4'- tetramethoxyflavone (= gossypetin 3,7,8,4'-tetramethyl ether) (11), and, unexpectedly, 5,7,3'-trihydroxy-3,6,8,4'-tetramethoxyflavone (12) and 5,3'-dihydroxy-8-dimethylamino-3,6,7,4'-tetramethoxyflavone (= 8-dimethylaminocasticin) (13). Cytotoxicity and antitubulin activity of these five flavones, as well as 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (= ayanin) (14) and intermediate 6,8-dibromo-ayanin (8), were evaluated. Comparison of the responses confirmed and clarified the influence of the A-ring substitution pattern on the biological activity.
- Lewin, Guy,MacIuk, Alexandre,Thoret, Sylviane,Aubert, Genevieve,Dubois, Joelle,Cresteil, Thierry
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experimental part
p. 702 - 706
(2010/08/22)
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