The Synthesis and Biological Evaluation of some Phloroglucinol-based Chalcones and Chromanones

Abstract

A novel series of 2’,4’,6’-trimethoxychalcone derivatives were prepared using one-step Claisen-Schmidt condensations of aldehydes with methyl ketones. The compounds were evaluated for effects against malaria, 15-lipoxygenase and radical scavenging activity. Of the twenty-five chalcone derivatives, only one exhibited significant scavenging of DPPH radical: E-1-(2,4,6-trimethoxyphenyl)-3-(3,4-dihydroxyphenyl)-2-propen-1-one (44). Almost all chalcone compounds showed potent inhibition of 15-lipoxygenase. Two 2’,4’-dimethoxy-6’-hydroxychalcone derivatives were synthesized by the same method. In most cases, chalcones containing a 6’-hydroxyl group cyclized spontaneously to chromanone. This provided four chroman-4-one derivatives, which were alkylated to yield chromanol derivatives. Hydrogenation of the chromanols afforded the corresponding chromans.