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

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 mu M), 22 (IC50=12.5 mu M), 3 (IC50=16.3 mu M), 11 (IC50=17.5 mu M) and 8 (IC50=21.3 mu M) showed significant inhibitory potential against lipoxygenase (baicalein, IC50=22.4M). On the other hand compound 19 (IC50=33.6 mu M) also showed strong antioxidant activity compared to the standard (IC50=44.7 mu M). This study is likely to lead to the discovery of therapeutically efficient agents against very important disorders including inflammation, asthma, cancer and autoimmune diseases.