Effect of Flavonol Derivatives on the Carrageenin-Induced Paw Edema in the Rat and Inhibition of Cyclooxygenase-1 and 5-Lipoxygenase in Vitro

Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chromen-4-one (6), 2-(4-ethoxyphenyl)-3-hydroxy-4H-chromen-4-one (7), 2-(4-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (10), and 2-(3-n-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (11) as well as the trihydroxy derivative 3-hydroxy-2-(3,4,5-trihydroxyphenyl)-4H-chromen-4-one (18) displayed high anti-inflammatory activity in carrageenin-induced rat paw edema. Additionally, the inhibition of enzymes of the arachidonic acid cascade by the derivatives w…