Mild and efficient synthesis of new tetraketones as lipoxygenase inhibitors and antioxidants

Abstract

A mild and efficient route to tetraketones (2–22) has been developed by way of tetraethyl ammonium bromide (Et₄N⁺Br⁻ ) mediated condensation of dimedone (5,5-dimethylcyclohexane-1,3-dione, 1) with a variety of aldehydes. All these compounds showed significant lipoxygenase inhibitory activity and moderate to strong antioxidant potential. Compounds 19 (IC₅₀ = 7.8 μM), 22 (IC₅₀ = 12.5 μM), 3 (IC₅₀ = 16.3 μM), 11 (IC₅₀ = 17.5 μM) and 8 (IC₅₀ = 21.3 μM) showed significant inhibitory potential against lipoxygenase (baicalein, IC₅₀ = 22.4 μM). On the other hand compound 19 (IC₅₀ = 33.6 μM) also showed strong antioxidant activity compared to the standard (IC₅₀ = 44.7 μM). This study is likely to lead to the discovery of therapeutically efficient agents against very important disorders including inflammation, asthma, cancer and autoimmune diseases.

Keywords::

• Tetraketones
• Inhibitory activity
• Lipoxygenase
• Antioxidant