Synthesis, Characterization And Property Studies Of Benzo-15-crown-5 Curcumin Derivatives

Curcumin has anti-inflammatory, antioxidant, hypolipidemic and antibacterial effects. After crown ether compound derivatived curcumin, the derivatives have broad application and can be complexed with metal ions to change the properties of the compound. Crown ether compounds have a unique cavity, which make it have special ligand selectivity for different metal ions. Crown ether complexes can reduce the toxicity of crown ethers.4-carboxy-benzo-15-crown-5 is an important organic synthesis intermediate. Tetraethylene glycol p-toluenesulfonate ester was synthesized by Bis[2-(2-hydroxyethoxy)ethyl] ether and Tosyl chloride.4-ethoxycarbonyl-benzo-15-crown-5 was synthesized by Tetraethylene glycol p-toluenesulfonate esterand ethyl 3,4-dihydroxy-benzoate.4-carboxy-benzo-15-crown-5 was obtained by hydrolysis of 4-ethoxycarbonyl-benzo-15-crown-5. The 4-carboxy-benzo-15-crown-5 of structure was characterized by infrared spectroscopy(IR).In this paper,12 kinds of compounds were synthesized which include four curcumin derivative ligands(L1-L4) and eightmetal complexes (CuL12、CuL22、CuL32、 CuL42、NaSCN·L1、 NaSCN·L3、Cu(NaSCNL1)2、Cu(NaSCNL3)2.Four curcumin derivative ligands and eight metal complexes were characterized by infrared spectroscopy(IR), NMR spectroscopy, UV-visible absorption spectroscopy(UV) and fluorescence spectroscopy. At the same time, the research investigated the optical properties of ligandsand complexes by UV-visible absorption spectroscopy and fluorescence spectroscopy. The results showed that the optical properties of derivatives are related to the polar properties of solvent and the optical properties of complexes have changed compared with ligand. This study also received complexes standard curve and the detection limit which provides a new approach to detect copper ions and sodium ions.In this paper, biological activity of four different derivatives and complexes was studied and analysed which mainly included antioxidant capacity and the ability of anti-cancer cells (plf-5, LX-2, MCF-7 and PC-12 cells) compared with curcumin. The antioxidant activity of crown ethers derived curcumin complexes have obviously improved; while crown ether curcumin derivatives have certain anti-cancer activity which was worse than curcumin which indicated that the anti-cancer activity site of curcumin was its phenolic hydroxyl group.After derivatived by copper ions, the anti-cancer activity of compounds was not improved, which indicate that complexes of copper ions are impossible to improve the antitumor activity of the derivatives.