Studies of the Synthesis and the Structure-activity Relationship of 3-Methylflavones

Background/aim: Flavonoids represent a privileged scaffold for medicinal chemists because of versatile synthetic transformation into a large variety of functionalized derivatives and are known to exhibit a variety of biological activities and their potential as anticancer agents is being investigated. As part of our continuing investigation of flavonoid derivatives as potential anticancer substances, a series of 3-methylflavones were synthesized, and their antiproliferative activity was evaluated in leukemic HL60 cells.

Materials and methods: 3-Methylflavones were directly synthesized from the 2-propionylphenyl benzoate esters prepared from combination of 2'-hydroxypropiophenone with appropriate benzoic acid derivatives by the modified conditions of Yamaguchi esterification. The synthesized 3-methylflavones were tested in leukemic HL60 cells to assess their antiproliferative activity.

Results: Among the synthesized compounds, 3,3'-dimethylflavone showed the most potent activity (IC₅₀=76 μM), although the introduction of C3-methyl group in flavone tended to reduce the biological activity.

Conclusion: Synthesis of a series of 3-methylflavones as anticancer agents conducted and their antiproliferative activity evaluated. Although the one carbon homologation at C3 position of flavones weakened their activity, atropisomerism can be highlighted as the remarkable phenomenon of 3-methylflavones.