ISOFLAVANS DERIVATIVES AS INHIBITORS OF SOYBEAN LIPOXYGENASE: IN-VITRO AND DOCKING STUDIES

Abstract

ABSTRACT The lipoxygenases (LOX) are a family of non-heme iron-containing dioxygenases which catalyze the stereospecific insertion of molecular oxygen into arachidonic acid, leading to hydroxy derivatives as end products. In this work, we studied the behavior of seven isoflavans on 15-soybean lipoxygenases (15-sLOX), comparing them with the known inhibitors quercetin and 3, 4-dihydroxybenzoic acid. Four of the seven investigated isoflavans showed IC 50 values smaller than 50 µM, being more potent than quercetin or 3, 4-dihydroxybenzoic acid. Besides a catecholic pattern, the presence of an aromatic ring B seems to confer additional activity to these compounds, a result which was rationalized by docking studies of these isoflavanss into the enzyme binding site. Keywords: Soybean Lipoxygenase, Isoflavans Inhibitors, IC 50 Values, Docking. INTRODUCTION The lipoxygenases (LOX) are a family of non-heme iron-containing dioxygenases which catalyze the stereospecific insertion of molecular oxygen into arachidonic acid [1], are classified with respect to their positional specificity of arachidonic acid oxygenation and are referred to as 5-, 8-, 12- and 15-LOX [2,3]. The biological properties of human lipoxygenases (hLOX) have been extensively studied due to their involvement in several diseases including bronchial asthma, allergic rhinitis, inflammatory, skin diseases, rheumatoid arthritis (5-hLOX) [4], cancer, osteoporosis and cardiovascular diseases prostatic cancer and asthma (15-hLOX) [5] and breast cancer and psoriasis (12-hLOX) [6, 7].The search for new LOX inhibitors has led to the synthesis and evaluation of a series of 3-aryl-3,4-dihydro-2-H-1-benzopyran or isoflavans derivatives in our laboratories [8]. Some of these compounds were found to exhibit interesting activities as inhibitors of soybean lipoxygenase-1 (sLOX); their IC