4,5-Diaryl 3(2H)Furanones: Anti-Inflammatory Activity and Influence on Cancer Growth

Apart from their anti-inflammatory action, COX inhibitors have gathered the interest of many scientists due to their potential use for the treatment and prevention of cancer. It has been shown that cyclooxygenase inhibitors restrict cancer cell growth and are able to interact with known antitumor drugs, enhancing their in vitro and in vivo cytotoxicity. The permutation of hydrophilic and hydrophobic aryl groups in COX inhibitors leads to cardinal changes in the biological activity of the compounds. In the present study, thirteen heterocyclic coxib-like 4,5-diarylfuran-3(2H)-ones and their annelated derivatives—phenanthro[9,10-b]furan-3-ones—were synthesized and studied for anti-inflammatory and COX-1/2 inhibitory action and for their cytotoxic activity on the breast cancer (MCF-7) and squamous cell carcinoma (HSC-3) cell lines. The F-derivative of the –SOMe substituted furan-3(2H)-ones exhibited the best activity (COX-1 IC50 = 2.8 μM, anti-inflammatory activity (by carrageenan paw edema model) of 54% (dose 0.01 mmol/kg), and MCF-7 and HSC-3 cytotoxicity with IC50 values of 10 μM and 7.5 μM, respectively). A cytotoxic effect related to the COX-1 inhibitory action was observed and a synergistic effect with the anti-neoplastic drugs gefitinib and 5-fluorouracil was found. A phenanthrene derivative exhibited the best synergistic effect with gefitinib.


1.Structures of known COX-1/2 inhibitors (E1-E14 ) used for prediction of inhibitory action
. Structures of known COX-1/2 inhibitors (E1-E14 ) 2. Synthesis of auxiliary compounds S3 Scheme S1. Synthesis of starting diaryl ketones by oxidation of substituted toluenes or benzaldehydes. For m-F substituted compounds Schiemann reaction is the most rational (Table S1) Table S1. Yields of the synthesis of starting diaryl ketones and their precursors according to Scheme S1.

S4
In the next stage to p-fluorobenzoic acid (4.96 g) in CCL4 (25ml) fresh SOCl2 (4ml) and DMFA (0.05 ml) in CCl4 (25 ml)were added. The mixture was refluxed during 5 hours until the end of release of gaseous products. The solvent and excess of SOCl2 were removed in vacuum. Obtained oil (5.6 g ,97 % of theoretical yield) , without additional purification, was dissolved in cold DCM (20 mL). This solution was added dropwise to cold suspension of AlCl3 (5 g) and thioanisole (4.38 g ,35 mmol) in of DCM (30 mL).

3.General procedure for the synthesis of 2.2-dimethyl-4,5-diphenylfuran-3(2H)-one
To a solution of diazoketone 4 (1 mmol )in CHCl3 (10mL) a trifluoroacetic acid (TFA, 0.1 mL) in CHCl3 (5 mL) was added. The mixture was refluxed during 2 hours until complete decomposition of the initial diazoketone (controlled by TLC). After the reaction completion the mixture was washed by water/NaHCO3, pure water (2х10 mL) and dried over K2CO3 (24 h). After removal of the solvent, about 0.9 mmol (~ 98%) of a mixture of two regioisomeric 2,2-dialkyl-4,5-diaryl-dihydrofuran-3(2H)-ones 3 (approximate ratio -3:1) was obtained as a light yellow oil. The regioisomers were separated by repeated twice chromatography on plates (or on column, eluent: nhexane/CH2Cl2) and around 0.66 mmol (~ 72 %) of desired 3(2H)furanone was obtained, slightly yellow crystals. The compounds 3 were described previously [38, Figure S2. Assessment of cell growth of MCF-7 cells in culture after their treatment with increasing concentrations of the tested compounds for 48 hours. Cell growth was assessed using a hemocytometer (Neubauer chamber) and is expressed as a percentage (%) relative to that for the untreated, control culture CTL). The data shown above indicate a representative experiment where 4 independent measurements for each concentration were used to calculate the average (± SD, Standard Deviation).

Compute modeling of pharmacological activity
List of the common terms and abbreviations used in the field of virtual screening.
Docking -computational approach to perform 3D analysis of supramolecular interactions between a ligand and biological target; • Pre-processing -energy minimization procedure and optimization of a biomolecular structure as well as ligand to obtain reliable 3D coordinates using the classical methods of molecular mechanics and dynamics; • Annealing -reconstruction of 3D structure of selected protein with a potential energy close to the predicted minimum; • Stress -conformational clashes of amino acid residues observed within the constructed protein structure; • Dock Scoring -energetic function (kcal/mol) routinely used for the assessment of ligand affinity towards a target; • RMSD -Root-mean-square deviation of atomic position. (c) Figure S3 (a, b, c). Potential energy (NormEnergy, kcal/mol) shared by amino acids in hCOX-2 (a) and hCOX-1 (b) after annealing; c) amino acids in hCOX-1 with high energy values (grey spheres); the binding site (yellow sphere).